config: add more method

DefaultString(key string, defaultval string) string      // support
section::key type in key string when using ini and json type;
Int,Int64,Bool,Float,DIY are same.
	DefaultStrings(key string, defaultval []string) []string //get string
slice
	DefaultInt(key string, defaultval int) int
	DefaultInt64(key string, defaultval int64) int64
	DefaultBool(key string, defaultval bool) bool
	DefaultFloat(key string, defaultval float64) float64
	DIY(key string) (interface{}, error)
	GetSection(section string) (map[string]string, error)
	SaveConfigFile(filename string) error

@@ -22,12 +22,21 @@ type ConfigContainer interface {
 	Int64(key string) (int64, error)
 	Int64(key string) (int64, error)
 	Bool(key string) (bool, error)
 	Bool(key string) (bool, error)
 	Float(key string) (float64, error)
 	Float(key string) (float64, error)
+	DefaultString(key string, defaultval string) string      // support section::key type in key string when using ini and json type; Int,Int64,Bool,Float,DIY are same.
+	DefaultStrings(key string, defaultval []string) []string //get string slice
+	DefaultInt(key string, defaultval int) int
+	DefaultInt64(key string, defaultval int64) int64
+	DefaultBool(key string, defaultval bool) bool
+	DefaultFloat(key string, defaultval float64) float64
 	DIY(key string) (interface{}, error)
 	DIY(key string) (interface{}, error)
+	GetSection(section string) (map[string]string, error)
+	SaveConfigFile(filename string) error
 }
 }
 
 
 // Config is the adapter interface for parsing config file to get raw data to ConfigContainer.
 // Config is the adapter interface for parsing config file to get raw data to ConfigContainer.
 type Config interface {
 type Config interface {
 	Parse(key string) (ConfigContainer, error)
 	Parse(key string) (ConfigContainer, error)
+	ParseData(data []byte) (ConfigContainer, error)
 }
 }
 
 
 var adapters = make(map[string]Config)
 var adapters = make(map[string]Config)
@@ -54,3 +63,13 @@ func NewConfig(adapterName, fileaname string) (ConfigContainer, error) {
 	}
 	}
 	return adapter.Parse(fileaname)
 	return adapter.Parse(fileaname)
 }
 }
+
+// adapterName is ini/json/xml/yaml.
+// data is the config data.
+func NewConfigData(adapterName string, data []byte) (ConfigContainer, error) {
+	adapter, ok := adapters[adapterName]
+	if !ok {
+		return nil, fmt.Errorf("config: unknown adaptername %q (forgotten import?)", adapterName)
+	}
+	return adapter.ParseData(data)
+}

@@ -32,26 +32,74 @@ func (c *fakeConfigContainer) String(key string) string {
 	return c.getData(key)
 	return c.getData(key)
 }
 }
 
 
+func (c *fakeConfigContainer) DefaultString(key string, defaultval string) string {
+	if v := c.getData(key); v == "" {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 func (c *fakeConfigContainer) Strings(key string) []string {
 func (c *fakeConfigContainer) Strings(key string) []string {
 	return strings.Split(c.getData(key), ";")
 	return strings.Split(c.getData(key), ";")
 }
 }
 
 
+func (c *fakeConfigContainer) DefaultStrings(key string, defaultval []string) []string {
+	if v := c.Strings(key); len(v) == 0 {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 func (c *fakeConfigContainer) Int(key string) (int, error) {
 func (c *fakeConfigContainer) Int(key string) (int, error) {
 	return strconv.Atoi(c.getData(key))
 	return strconv.Atoi(c.getData(key))
 }
 }
 
 
+func (c *fakeConfigContainer) DefaultInt(key string, defaultval int) int {
+	if v, err := c.Int(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 func (c *fakeConfigContainer) Int64(key string) (int64, error) {
 func (c *fakeConfigContainer) Int64(key string) (int64, error) {
 	return strconv.ParseInt(c.getData(key), 10, 64)
 	return strconv.ParseInt(c.getData(key), 10, 64)
 }
 }
 
 
+func (c *fakeConfigContainer) DefaultInt64(key string, defaultval int64) int64 {
+	if v, err := c.Int64(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 func (c *fakeConfigContainer) Bool(key string) (bool, error) {
 func (c *fakeConfigContainer) Bool(key string) (bool, error) {
 	return strconv.ParseBool(c.getData(key))
 	return strconv.ParseBool(c.getData(key))
 }
 }
 
 
+func (c *fakeConfigContainer) DefaultBool(key string, defaultval bool) bool {
+	if v, err := c.Bool(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 func (c *fakeConfigContainer) Float(key string) (float64, error) {
 func (c *fakeConfigContainer) Float(key string) (float64, error) {
 	return strconv.ParseFloat(c.getData(key), 64)
 	return strconv.ParseFloat(c.getData(key), 64)
 }
 }
 
 
+func (c *fakeConfigContainer) DefaultFloat(key string, defaultval float64) float64 {
+	if v, err := c.Float(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 func (c *fakeConfigContainer) DIY(key string) (interface{}, error) {
 func (c *fakeConfigContainer) DIY(key string) (interface{}, error) {
 	if v, ok := c.data[strings.ToLower(key)]; ok {
 	if v, ok := c.data[strings.ToLower(key)]; ok {
 		return v, nil
 		return v, nil
@@ -59,6 +107,14 @@ func (c *fakeConfigContainer) DIY(key string) (interface{}, error) {
 	return nil, errors.New("key not find")
 	return nil, errors.New("key not find")
 }
 }
 
 
+func (c *fakeConfigContainer) GetSection(section string) (map[string]string, error) {
+	return nil, errors.New("not implement in the fakeConfigContainer")
+}
+
+func (c *fakeConfigContainer) SaveConfigFile(filename string) error {
+	return errors.New("not implement in the fakeConfigContainer")
+}
+
 var _ ConfigContainer = new(fakeConfigContainer)
 var _ ConfigContainer = new(fakeConfigContainer)
 
 
 func NewFakeConfig() ConfigContainer {
 func NewFakeConfig() ConfigContainer {

@@ -13,11 +13,15 @@ import (
 	"bufio"
 	"bufio"
 	"bytes"
 	"bytes"
 	"errors"
 	"errors"
+	"fmt"
 	"io"
 	"io"
+	"io/ioutil"
 	"os"
 	"os"
+	"path"
 	"strconv"
 	"strconv"
 	"strings"
 	"strings"
 	"sync"
 	"sync"
+	"time"
 	"unicode"
 	"unicode"
 )
 )
 
 
@@ -30,6 +34,7 @@ var (
 	bDQuote         = []byte{'"'} // quote signal
 	bDQuote         = []byte{'"'} // quote signal
 	sectionStart    = []byte{'['} // section start signal
 	sectionStart    = []byte{'['} // section start signal
 	sectionEnd      = []byte{']'} // section end signal
 	sectionEnd      = []byte{']'} // section end signal
+	lineBreak       = "\n"
 )
 )
 
 
 // IniConfig implements Config to parse ini file.
 // IniConfig implements Config to parse ini file.
@@ -115,6 +120,16 @@ func (ini *IniConfig) Parse(name string) (ConfigContainer, error) {
 	return cfg, nil
 	return cfg, nil
 }
 }
 
 
+func (ini *IniConfig) ParseData(data []byte) (ConfigContainer, error) {
+	// Save memory data to temporary file
+	tmpName := path.Join(os.TempDir(), "beego", fmt.Sprintf("%d", time.Now().Nanosecond()))
+	os.MkdirAll(path.Dir(tmpName), os.ModePerm)
+	if err := ioutil.WriteFile(tmpName, data, 0655); err != nil {
+		return nil, err
+	}
+	return ini.Parse(tmpName)
+}
+
 // A Config represents the ini configuration.
 // A Config represents the ini configuration.
 // When set and get value, support key as section:name type.
 // When set and get value, support key as section:name type.
 type IniConfigContainer struct {
 type IniConfigContainer struct {
@@ -130,32 +145,154 @@ func (c *IniConfigContainer) Bool(key string) (bool, error) {
 	return strconv.ParseBool(c.getdata(strings.ToLower(key)))
 	return strconv.ParseBool(c.getdata(strings.ToLower(key)))
 }
 }
 
 
+// DefaultBool returns the boolean value for a given key.
+// if err != nil return defaltval
+func (c *IniConfigContainer) DefaultBool(key string, defaultval bool) bool {
+	if v, err := c.Bool(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Int returns the integer value for a given key.
 // Int returns the integer value for a given key.
 func (c *IniConfigContainer) Int(key string) (int, error) {
 func (c *IniConfigContainer) Int(key string) (int, error) {
 	return strconv.Atoi(c.getdata(strings.ToLower(key)))
 	return strconv.Atoi(c.getdata(strings.ToLower(key)))
 }
 }
 
 
+// DefaultInt returns the integer value for a given key.
+// if err != nil return defaltval
+func (c *IniConfigContainer) DefaultInt(key string, defaultval int) int {
+	if v, err := c.Int(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Int64 returns the int64 value for a given key.
 // Int64 returns the int64 value for a given key.
 func (c *IniConfigContainer) Int64(key string) (int64, error) {
 func (c *IniConfigContainer) Int64(key string) (int64, error) {
 	return strconv.ParseInt(c.getdata(strings.ToLower(key)), 10, 64)
 	return strconv.ParseInt(c.getdata(strings.ToLower(key)), 10, 64)
 }
 }
 
 
+// DefaultInt64 returns the int64 value for a given key.
+// if err != nil return defaltval
+func (c *IniConfigContainer) DefaultInt64(key string, defaultval int64) int64 {
+	if v, err := c.Int64(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Float returns the float value for a given key.
 // Float returns the float value for a given key.
 func (c *IniConfigContainer) Float(key string) (float64, error) {
 func (c *IniConfigContainer) Float(key string) (float64, error) {
 	return strconv.ParseFloat(c.getdata(strings.ToLower(key)), 64)
 	return strconv.ParseFloat(c.getdata(strings.ToLower(key)), 64)
 }
 }
 
 
+// DefaultFloat returns the float64 value for a given key.
+// if err != nil return defaltval
+func (c *IniConfigContainer) DefaultFloat(key string, defaultval float64) float64 {
+	if v, err := c.Float(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // String returns the string value for a given key.
 // String returns the string value for a given key.
 func (c *IniConfigContainer) String(key string) string {
 func (c *IniConfigContainer) String(key string) string {
 	key = strings.ToLower(key)
 	key = strings.ToLower(key)
 	return c.getdata(strings.ToLower(key))
 	return c.getdata(strings.ToLower(key))
 }
 }
 
 
+// DefaultString returns the string value for a given key.
+// if err != nil return defaltval
+func (c *IniConfigContainer) DefaultString(key string, defaultval string) string {
+	if v := c.String(key); v == "" {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Strings returns the []string value for a given key.
 // Strings returns the []string value for a given key.
 func (c *IniConfigContainer) Strings(key string) []string {
 func (c *IniConfigContainer) Strings(key string) []string {
 	return strings.Split(c.String(key), ";")
 	return strings.Split(c.String(key), ";")
 }
 }
 
 
+// DefaultStrings returns the []string value for a given key.
+// if err != nil return defaltval
+func (c *IniConfigContainer) DefaultStrings(key string, defaultval []string) []string {
+	if v := c.Strings(key); len(v) == 0 {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
+// GetSection returns map for the given section
+func (c *IniConfigContainer) GetSection(section string) (map[string]string, error) {
+	if v, ok := c.data[section]; ok {
+		return v, nil
+	} else {
+		return nil, errors.New("not exist setction")
+	}
+}
+
+// SaveConfigFile save the config into file
+func (c *IniConfigContainer) SaveConfigFile(filename string) (err error) {
+	// Write configuration file by filename.
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	buf := bytes.NewBuffer(nil)
+	for section, dt := range c.data {
+		// Write section comments.
+		if v, ok := c.sectionComment[section]; ok {
+			if _, err = buf.WriteString(string(bNumComment) + v + lineBreak); err != nil {
+				return err
+			}
+		}
+
+		if section != DEFAULT_SECTION {
+			// Write section name.
+			if _, err = buf.WriteString(string(sectionStart) + section + string(sectionEnd) + lineBreak); err != nil {
+				return err
+			}
+		}
+
+		for key, val := range dt {
+			if key != " " {
+				// Write key comments.
+				if v, ok := c.keyComment[key]; ok {
+					if _, err = buf.WriteString(string(bNumComment) + v + lineBreak); err != nil {
+						return err
+					}
+				}
+
+				// Write key and value.
+				if _, err = buf.WriteString(key + string(bEqual) + val + lineBreak); err != nil {
+					return err
+				}
+			}
+		}
+
+		// Put a line between sections.
+		if _, err = buf.WriteString(lineBreak); err != nil {
+			return err
+		}
+	}
+
+	if _, err = buf.WriteTo(f); err != nil {
+		return err
+	}
+	return nil
+}
+
 // WriteValue writes a new value for key.
 // WriteValue writes a new value for key.
 // if write to one section, the key need be "section::key".
 // if write to one section, the key need be "section::key".
 // if the section is not existed, it panics.
 // if the section is not existed, it panics.

@@ -12,10 +12,13 @@ package config
 import (
 import (
 	"encoding/json"
 	"encoding/json"
 	"errors"
 	"errors"
+	"fmt"
 	"io/ioutil"
 	"io/ioutil"
 	"os"
 	"os"
+	"path"
 	"strings"
 	"strings"
 	"sync"
 	"sync"
+	"time"
 )
 )
 
 
 // JsonConfig is a json config parser and implements Config interface.
 // JsonConfig is a json config parser and implements Config interface.
@@ -48,6 +51,16 @@ func (js *JsonConfig) Parse(filename string) (ConfigContainer, error) {
 	return x, nil
 	return x, nil
 }
 }
 
 
+func (js *JsonConfig) ParseData(data []byte) (ConfigContainer, error) {
+	// Save memory data to temporary file
+	tmpName := path.Join(os.TempDir(), "beego", fmt.Sprintf("%d", time.Now().Nanosecond()))
+	os.MkdirAll(path.Dir(tmpName), os.ModePerm)
+	if err := ioutil.WriteFile(tmpName, data, 0655); err != nil {
+		return nil, err
+	}
+	return js.Parse(tmpName)
+}
+
 // A Config represents the json configuration.
 // A Config represents the json configuration.
 // Only when get value, support key as section:name type.
 // Only when get value, support key as section:name type.
 type JsonConfigContainer struct {
 type JsonConfigContainer struct {
@@ -67,6 +80,16 @@ func (c *JsonConfigContainer) Bool(key string) (bool, error) {
 	return false, errors.New("not exist key:" + key)
 	return false, errors.New("not exist key:" + key)
 }
 }
 
 
+// DefaultBool return the bool value if has no error
+// otherwise return the defaultval
+func (c *JsonConfigContainer) DefaultBool(key string, defaultval bool) bool {
+	if v, err := c.Bool(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Int returns the integer value for a given key.
 // Int returns the integer value for a given key.
 func (c *JsonConfigContainer) Int(key string) (int, error) {
 func (c *JsonConfigContainer) Int(key string) (int, error) {
 	val := c.getData(key)
 	val := c.getData(key)
@@ -79,6 +102,16 @@ func (c *JsonConfigContainer) Int(key string) (int, error) {
 	return 0, errors.New("not exist key:" + key)
 	return 0, errors.New("not exist key:" + key)
 }
 }
 
 
+// DefaultInt returns the integer value for a given key.
+// if err != nil return defaltval
+func (c *JsonConfigContainer) DefaultInt(key string, defaultval int) int {
+	if v, err := c.Int(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Int64 returns the int64 value for a given key.
 // Int64 returns the int64 value for a given key.
 func (c *JsonConfigContainer) Int64(key string) (int64, error) {
 func (c *JsonConfigContainer) Int64(key string) (int64, error) {
 	val := c.getData(key)
 	val := c.getData(key)
@@ -91,6 +124,16 @@ func (c *JsonConfigContainer) Int64(key string) (int64, error) {
 	return 0, errors.New("not exist key:" + key)
 	return 0, errors.New("not exist key:" + key)
 }
 }
 
 
+// DefaultInt64 returns the int64 value for a given key.
+// if err != nil return defaltval
+func (c *JsonConfigContainer) DefaultInt64(key string, defaultval int64) int64 {
+	if v, err := c.Int64(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Float returns the float value for a given key.
 // Float returns the float value for a given key.
 func (c *JsonConfigContainer) Float(key string) (float64, error) {
 func (c *JsonConfigContainer) Float(key string) (float64, error) {
 	val := c.getData(key)
 	val := c.getData(key)
@@ -103,6 +146,16 @@ func (c *JsonConfigContainer) Float(key string) (float64, error) {
 	return 0.0, errors.New("not exist key:" + key)
 	return 0.0, errors.New("not exist key:" + key)
 }
 }
 
 
+// DefaultFloat returns the float64 value for a given key.
+// if err != nil return defaltval
+func (c *JsonConfigContainer) DefaultFloat(key string, defaultval float64) float64 {
+	if v, err := c.Float(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // String returns the string value for a given key.
 // String returns the string value for a given key.
 func (c *JsonConfigContainer) String(key string) string {
 func (c *JsonConfigContainer) String(key string) string {
 	val := c.getData(key)
 	val := c.getData(key)
@@ -114,11 +167,56 @@ func (c *JsonConfigContainer) String(key string) string {
 	return ""
 	return ""
 }
 }
 
 
+// DefaultString returns the string value for a given key.
+// if err != nil return defaltval
+func (c *JsonConfigContainer) DefaultString(key string, defaultval string) string {
+	if v := c.String(key); v == "" {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Strings returns the []string value for a given key.
 // Strings returns the []string value for a given key.
 func (c *JsonConfigContainer) Strings(key string) []string {
 func (c *JsonConfigContainer) Strings(key string) []string {
 	return strings.Split(c.String(key), ";")
 	return strings.Split(c.String(key), ";")
 }
 }
 
 
+// DefaultStrings returns the []string value for a given key.
+// if err != nil return defaltval
+func (c *JsonConfigContainer) DefaultStrings(key string, defaultval []string) []string {
+	if v := c.Strings(key); len(v) == 0 {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
+// GetSection returns map for the given section
+func (c *JsonConfigContainer) GetSection(section string) (map[string]string, error) {
+	if v, ok := c.data[section]; ok {
+		return v.(map[string]string), nil
+	} else {
+		return nil, errors.New("not exist setction")
+	}
+}
+
+// SaveConfigFile save the config into file
+func (c *JsonConfigContainer) SaveConfigFile(filename string) (err error) {
+	// Write configuration file by filename.
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	b, err := json.MarshalIndent(c.data, "", "  ")
+	if err != nil {
+		return err
+	}
+	_, err = f.Write(b)
+	return err
+}
+
 // WriteValue writes a new value for key.
 // WriteValue writes a new value for key.
 func (c *JsonConfigContainer) Set(key, val string) error {
 func (c *JsonConfigContainer) Set(key, val string) error {
 	c.Lock()
 	c.Lock()

@@ -10,12 +10,16 @@
 package xml
 package xml
 
 
 import (
 import (
+	"encoding/xml"
 	"errors"
 	"errors"
+	"fmt"
 	"io/ioutil"
 	"io/ioutil"
 	"os"
 	"os"
+	"path"
 	"strconv"
 	"strconv"
 	"strings"
 	"strings"
 	"sync"
 	"sync"
+	"time"
 
 
 	"github.com/astaxie/beego/config"
 	"github.com/astaxie/beego/config"
 	"github.com/beego/x2j"
 	"github.com/beego/x2j"
@@ -49,6 +53,16 @@ func (xc *XMLConfig) Parse(filename string) (config.ConfigContainer, error) {
 	return x, nil
 	return x, nil
 }
 }
 
 
+func (x *XMLConfig) ParseData(data []byte) (config.ConfigContainer, error) {
+	// Save memory data to temporary file
+	tmpName := path.Join(os.TempDir(), "beego", fmt.Sprintf("%d", time.Now().Nanosecond()))
+	os.MkdirAll(path.Dir(tmpName), os.ModePerm)
+	if err := ioutil.WriteFile(tmpName, data, 0655); err != nil {
+		return nil, err
+	}
+	return x.Parse(tmpName)
+}
+
 // A Config represents the xml configuration.
 // A Config represents the xml configuration.
 type XMLConfigContainer struct {
 type XMLConfigContainer struct {
 	data map[string]interface{}
 	data map[string]interface{}
@@ -60,21 +74,61 @@ func (c *XMLConfigContainer) Bool(key string) (bool, error) {
 	return strconv.ParseBool(c.data[key].(string))
 	return strconv.ParseBool(c.data[key].(string))
 }
 }
 
 
+// DefaultBool return the bool value if has no error
+// otherwise return the defaultval
+func (c *XMLConfigContainer) DefaultBool(key string, defaultval bool) bool {
+	if v, err := c.Bool(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Int returns the integer value for a given key.
 // Int returns the integer value for a given key.
 func (c *XMLConfigContainer) Int(key string) (int, error) {
 func (c *XMLConfigContainer) Int(key string) (int, error) {
 	return strconv.Atoi(c.data[key].(string))
 	return strconv.Atoi(c.data[key].(string))
 }
 }
 
 
+// DefaultInt returns the integer value for a given key.
+// if err != nil return defaltval
+func (c *XMLConfigContainer) DefaultInt(key string, defaultval int) int {
+	if v, err := c.Int(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Int64 returns the int64 value for a given key.
 // Int64 returns the int64 value for a given key.
 func (c *XMLConfigContainer) Int64(key string) (int64, error) {
 func (c *XMLConfigContainer) Int64(key string) (int64, error) {
 	return strconv.ParseInt(c.data[key].(string), 10, 64)
 	return strconv.ParseInt(c.data[key].(string), 10, 64)
 }
 }
 
 
+// DefaultInt64 returns the int64 value for a given key.
+// if err != nil return defaltval
+func (c *XMLConfigContainer) DefaultInt64(key string, defaultval int64) int64 {
+	if v, err := c.Int64(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Float returns the float value for a given key.
 // Float returns the float value for a given key.
 func (c *XMLConfigContainer) Float(key string) (float64, error) {
 func (c *XMLConfigContainer) Float(key string) (float64, error) {
 	return strconv.ParseFloat(c.data[key].(string), 64)
 	return strconv.ParseFloat(c.data[key].(string), 64)
 }
 }
 
 
+// DefaultFloat returns the float64 value for a given key.
+// if err != nil return defaltval
+func (c *XMLConfigContainer) DefaultFloat(key string, defaultval float64) float64 {
+	if v, err := c.Float(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // String returns the string value for a given key.
 // String returns the string value for a given key.
 func (c *XMLConfigContainer) String(key string) string {
 func (c *XMLConfigContainer) String(key string) string {
 	if v, ok := c.data[key].(string); ok {
 	if v, ok := c.data[key].(string); ok {
@@ -83,11 +137,56 @@ func (c *XMLConfigContainer) String(key string) string {
 	return ""
 	return ""
 }
 }
 
 
+// DefaultString returns the string value for a given key.
+// if err != nil return defaltval
+func (c *XMLConfigContainer) DefaultString(key string, defaultval string) string {
+	if v := c.String(key); v == "" {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Strings returns the []string value for a given key.
 // Strings returns the []string value for a given key.
 func (c *XMLConfigContainer) Strings(key string) []string {
 func (c *XMLConfigContainer) Strings(key string) []string {
 	return strings.Split(c.String(key), ";")
 	return strings.Split(c.String(key), ";")
 }
 }
 
 
+// DefaultStrings returns the []string value for a given key.
+// if err != nil return defaltval
+func (c *XMLConfigContainer) DefaultStrings(key string, defaultval []string) []string {
+	if v := c.Strings(key); len(v) == 0 {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
+// GetSection returns map for the given section
+func (c *XMLConfigContainer) GetSection(section string) (map[string]string, error) {
+	if v, ok := c.data[section]; ok {
+		return v.(map[string]string), nil
+	} else {
+		return nil, errors.New("not exist setction")
+	}
+}
+
+// SaveConfigFile save the config into file
+func (c *XMLConfigContainer) SaveConfigFile(filename string) (err error) {
+	// Write configuration file by filename.
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	b, err := xml.MarshalIndent(c.data, "  ", "    ")
+	if err != nil {
+		return err
+	}
+	_, err = f.Write(b)
+	return err
+}
+
 // WriteValue writes a new value for key.
 // WriteValue writes a new value for key.
 func (c *XMLConfigContainer) Set(key, val string) error {
 func (c *XMLConfigContainer) Set(key, val string) error {
 	c.Lock()
 	c.Lock()

@@ -13,11 +13,14 @@ import (
 	"bytes"
 	"bytes"
 	"encoding/json"
 	"encoding/json"
 	"errors"
 	"errors"
+	"fmt"
 	"io/ioutil"
 	"io/ioutil"
 	"log"
 	"log"
 	"os"
 	"os"
+	"path"
 	"strings"
 	"strings"
 	"sync"
 	"sync"
+	"time"
 
 
 	"github.com/astaxie/beego/config"
 	"github.com/astaxie/beego/config"
 	"github.com/beego/goyaml2"
 	"github.com/beego/goyaml2"
@@ -38,6 +41,16 @@ func (yaml *YAMLConfig) Parse(filename string) (y config.ConfigContainer, err er
 	return
 	return
 }
 }
 
 
+func (yaml *YAMLConfig) ParseData(data []byte) (config.ConfigContainer, error) {
+	// Save memory data to temporary file
+	tmpName := path.Join(os.TempDir(), "beego", fmt.Sprintf("%d", time.Now().Nanosecond()))
+	os.MkdirAll(path.Dir(tmpName), os.ModePerm)
+	if err := ioutil.WriteFile(tmpName, data, 0655); err != nil {
+		return nil, err
+	}
+	return yaml.Parse(tmpName)
+}
+
 // Read yaml file to map.
 // Read yaml file to map.
 // if json like, use json package, unless goyaml2 package.
 // if json like, use json package, unless goyaml2 package.
 func ReadYmlReader(path string) (cnf map[string]interface{}, err error) {
 func ReadYmlReader(path string) (cnf map[string]interface{}, err error) {
@@ -93,6 +106,16 @@ func (c *YAMLConfigContainer) Bool(key string) (bool, error) {
 	return false, errors.New("not bool value")
 	return false, errors.New("not bool value")
 }
 }
 
 
+// DefaultBool return the bool value if has no error
+// otherwise return the defaultval
+func (c *YAMLConfigContainer) DefaultBool(key string, defaultval bool) bool {
+	if v, err := c.Bool(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Int returns the integer value for a given key.
 // Int returns the integer value for a given key.
 func (c *YAMLConfigContainer) Int(key string) (int, error) {
 func (c *YAMLConfigContainer) Int(key string) (int, error) {
 	if v, ok := c.data[key].(int64); ok {
 	if v, ok := c.data[key].(int64); ok {
@@ -101,6 +124,16 @@ func (c *YAMLConfigContainer) Int(key string) (int, error) {
 	return 0, errors.New("not int value")
 	return 0, errors.New("not int value")
 }
 }
 
 
+// DefaultInt returns the integer value for a given key.
+// if err != nil return defaltval
+func (c *YAMLConfigContainer) DefaultInt(key string, defaultval int) int {
+	if v, err := c.Int(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Int64 returns the int64 value for a given key.
 // Int64 returns the int64 value for a given key.
 func (c *YAMLConfigContainer) Int64(key string) (int64, error) {
 func (c *YAMLConfigContainer) Int64(key string) (int64, error) {
 	if v, ok := c.data[key].(int64); ok {
 	if v, ok := c.data[key].(int64); ok {
@@ -109,6 +142,16 @@ func (c *YAMLConfigContainer) Int64(key string) (int64, error) {
 	return 0, errors.New("not bool value")
 	return 0, errors.New("not bool value")
 }
 }
 
 
+// DefaultInt64 returns the int64 value for a given key.
+// if err != nil return defaltval
+func (c *YAMLConfigContainer) DefaultInt64(key string, defaultval int64) int64 {
+	if v, err := c.Int64(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Float returns the float value for a given key.
 // Float returns the float value for a given key.
 func (c *YAMLConfigContainer) Float(key string) (float64, error) {
 func (c *YAMLConfigContainer) Float(key string) (float64, error) {
 	if v, ok := c.data[key].(float64); ok {
 	if v, ok := c.data[key].(float64); ok {
@@ -117,6 +160,16 @@ func (c *YAMLConfigContainer) Float(key string) (float64, error) {
 	return 0.0, errors.New("not float64 value")
 	return 0.0, errors.New("not float64 value")
 }
 }
 
 
+// DefaultFloat returns the float64 value for a given key.
+// if err != nil return defaltval
+func (c *YAMLConfigContainer) DefaultFloat(key string, defaultval float64) float64 {
+	if v, err := c.Float(key); err != nil {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // String returns the string value for a given key.
 // String returns the string value for a given key.
 func (c *YAMLConfigContainer) String(key string) string {
 func (c *YAMLConfigContainer) String(key string) string {
 	if v, ok := c.data[key].(string); ok {
 	if v, ok := c.data[key].(string); ok {
@@ -125,11 +178,52 @@ func (c *YAMLConfigContainer) String(key string) string {
 	return ""
 	return ""
 }
 }
 
 
+// DefaultString returns the string value for a given key.
+// if err != nil return defaltval
+func (c *YAMLConfigContainer) DefaultString(key string, defaultval string) string {
+	if v := c.String(key); v == "" {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
 // Strings returns the []string value for a given key.
 // Strings returns the []string value for a given key.
 func (c *YAMLConfigContainer) Strings(key string) []string {
 func (c *YAMLConfigContainer) Strings(key string) []string {
 	return strings.Split(c.String(key), ";")
 	return strings.Split(c.String(key), ";")
 }
 }
 
 
+// DefaultStrings returns the []string value for a given key.
+// if err != nil return defaltval
+func (c *YAMLConfigContainer) DefaultStrings(key string, defaultval []string) []string {
+	if v := c.Strings(key); len(v) == 0 {
+		return defaultval
+	} else {
+		return v
+	}
+}
+
+// GetSection returns map for the given section
+func (c *YAMLConfigContainer) GetSection(section string) (map[string]string, error) {
+	if v, ok := c.data[section]; ok {
+		return v.(map[string]string), nil
+	} else {
+		return nil, errors.New("not exist setction")
+	}
+}
+
+// SaveConfigFile save the config into file
+func (c *YAMLConfigContainer) SaveConfigFile(filename string) (err error) {
+	// Write configuration file by filename.
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	err = goyaml2.Write(f, c.data)
+	return err
+}
+
 // WriteValue writes a new value for key.
 // WriteValue writes a new value for key.
 func (c *YAMLConfigContainer) Set(key, val string) error {
 func (c *YAMLConfigContainer) Set(key, val string) error {
 	c.Lock()
 	c.Lock()