add httplib support like http.client

docs/zh/HttpLib.md

+## 方便的http客户端
+我们经常会使用Go来请求其他API应用，例如你使用beego开发了一个RESTFul的API应用，那么如果来请求呢？当然可以使用`http.Client`来实现，但是需要自己来操作很多步骤，自己需要考虑很多东西，所以我就基于net下的一些包实现了这个简便的http客户端工具。
+
+该工具的主要特点：
+
+- 链式操作
+- 超时控制
+- 方便的解析
+- 可控的debug
+
+## 例子
+我们上次开发的RESTful应用，最后我写过如何通过curl来进行测试，那么下面一一对每个操作如何用httplib来操作进行展示
+
+- 添加一个对象：
+
+	`curl -X POST -d '{"Score":1337,"PlayerName":"Sean Plott"}' http://127.0.0.1:8080/object`
+	
+	返回一个相应的objectID:astaxie1373349756660423900
+	
+		str,err:=beego.Post("http://127.0.0.1:8080/object").Body(`{"Score":1337,"PlayerName":"Sean Plott"}`).String()
+		if err != nil{
+			println(err)
+		}
+	
+- 查询一个对象
+
+	`curl -X GET http://127.0.0.1:8080/object/astaxie1373349756660423900`
+	
+		var object Obeject
+		err:=beego.Get("http://127.0.0.1:8080/object/astaxie1373349756660423900").ToJson(&object)
+		if err != nil{
+			println(err)
+		}
+	
+- 查询全部的对象	
+
+	`curl -X GET http://127.0.0.1:8080/object`
+	
+		var objects []Object
+		err:=beego.Get("http://127.0.0.1:8080/object").ToJson(&objects)
+		if err != nil{
+			println(err)
+		}
+
+- 更新一个对象
+
+	`curl -X PUT -d '{"Score":10000}'http://127.0.0.1:8080/object/astaxie1373349756660423900`
+	
+		str,err:=beego.Put("http://127.0.0.1:8080/object/astaxie1373349756660423900").Body(`{"Score":10000}`).String()
+		if err != nil{
+			println(err)
+		}
+
+- 删除一个对象
+
+	`curl -X DELETE http://127.0.0.1:8080/object/astaxie1373349756660423900`
+	
+		str,er:=beego.Delete("http://127.0.0.1:8080/object/astaxie1373349756660423900").String()
+		if err != nil{
+			println(err)
+		}
+
+## 开启调试模式
+用户可以开启调试打印request信息，默认是关闭模式
+
+	beego.Post(url).Debug(true)
+
+## ToFile、ToXML、ToJson
+上面我演示了Json的解析，其实还有直接保存为文件的ToFile操作，解析XML的ToXML操作
+
+
+## 设置链接超时和读写超时
+默认都设置为60秒，用户可以通过函数来设置相应的超时时间
+
+	beego.Get(url).SetTimeout(100*time.Second,100*time.Second)
+
+
+更加详细的请参考[API接口](http://gowalker.org/github.com/astaxie/beego)
\ No newline at end of file

docs/zh/README.md

@@ -44,6 +44,7 @@ beego是一个类似tornado的Go应用框架，采用了RESTFul的方式来实
 * [beego案例](Application.md)
 * [热升级](HotUpdate.md)
 * [API应用开发入门](API.md)
+* [HTTPLIB客户端](HttpLib.md)
 
 
 # API接口

httplib.go

+package beego
+
+import (
+	"bytes"
+	"encoding/json"
+	"encoding/xml"
+	"io"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"os"
+	"strings"
+	"time"
+)
+
+var defaultUserAgent = "beegoServer"
+
+func Get(url string) *BeegoHttpRequest {
+	var req http.Request
+	req.Method = "GET"
+	req.Header = http.Header{}
+	req.Header.Set("User-Agent", defaultUserAgent)
+	return &BeegoHttpRequest{url, &req, map[string]string{}, false, 60 * time.Second, 60 * time.Second}
+}
+
+func Post(url string) *BeegoHttpRequest {
+	var req http.Request
+	req.Method = "POST"
+	req.Header = http.Header{}
+	req.Header.Set("User-Agent", defaultUserAgent)
+	return &BeegoHttpRequest{url, &req, map[string]string{}, false, 60 * time.Second, 60 * time.Second}
+}
+
+func Put(url string) *BeegoHttpRequest {
+	var req http.Request
+	req.Method = "PUT"
+	req.Header = http.Header{}
+	req.Header.Set("User-Agent", defaultUserAgent)
+	return &BeegoHttpRequest{url, &req, map[string]string{}, false, 60 * time.Second, 60 * time.Second}
+}
+
+func Delete(url string) *BeegoHttpRequest {
+	var req http.Request
+	req.Method = "DELETE"
+	req.Header = http.Header{}
+	req.Header.Set("User-Agent", defaultUserAgent)
+	return &BeegoHttpRequest{url, &req, map[string]string{}, false, 60 * time.Second, 60 * time.Second}
+}
+
+func Head(url string) *BeegoHttpRequest {
+	var req http.Request
+	req.Method = "HEAD"
+	req.Header = http.Header{}
+	req.Header.Set("User-Agent", defaultUserAgent)
+	return &BeegoHttpRequest{url, &req, map[string]string{}, false, 60 * time.Second, 60 * time.Second}
+}
+
+type BeegoHttpRequest struct {
+	url              string
+	req              *http.Request
+	params           map[string]string
+	showdebug        bool
+	connectTimeout   time.Duration
+	readWriteTimeout time.Duration
+}
+
+func (b *BeegoHttpRequest) Debug(isdebug bool) *BeegoHttpRequest {
+	b.showdebug = isdebug
+	return b
+}
+
+func (b *BeegoHttpRequest) SetTimeout(connectTimeout, readWriteTimeout time.Duration) *BeegoHttpRequest {
+	b.connectTimeout = connectTimeout
+	b.readWriteTimeout = readWriteTimeout
+	return b
+}
+
+func (b *BeegoHttpRequest) Header(key, value string) *BeegoHttpRequest {
+	b.req.Header.Set(key, value)
+	return b
+}
+
+func (b *BeegoHttpRequest) Param(key, value string) *BeegoHttpRequest {
+	b.params[key] = value
+	return b
+}
+
+func (b *BeegoHttpRequest) Body(data interface{}) *BeegoHttpRequest {
+	switch t := data.(type) {
+	case string:
+		bf := bytes.NewBufferString(t)
+		b.req.Body = ioutil.NopCloser(bf)
+		b.req.ContentLength = int64(len(t))
+	case []byte:
+		bf := bytes.NewBuffer(t)
+		b.req.Body = ioutil.NopCloser(bf)
+		b.req.ContentLength = int64(len(t))
+	}
+	return b
+}
+
+func (b *BeegoHttpRequest) getResponse() (*http.Response, error) {
+	var paramBody string
+	if b.params != nil && len(b.params) > 0 {
+		var buf bytes.Buffer
+		for k, v := range b.params {
+			buf.WriteString(url.QueryEscape(k))
+			buf.WriteByte('=')
+			buf.WriteString(url.QueryEscape(v))
+			buf.WriteByte('&')
+		}
+		paramBody = buf.String()
+		paramBody = paramBody[0 : len(paramBody)-1]
+	}
+	if b.req.Method == "GET" && len(paramBody) > 0 {
+		if strings.Index(b.url, "?") != -1 {
+			b.url += "&" + paramBody
+		} else {
+			b.url = b.url + "?" + paramBody
+		}
+	} else if b.req.Method == "POST" && b.req.Body == nil && len(paramBody) > 0 {
+		b.Header("Content-Type", "application/x-www-form-urlencoded")
+		b.Body(paramBody)
+	}
+
+	url, err := url.Parse(b.url)
+	if url.Scheme == "" {
+		b.url = "http://" + b.url
+		url, err = url.Parse(b.url)
+	}
+
+	if err != nil {
+		return nil, err
+	}
+	b.req.URL = url
+	if b.showdebug {
+		dump, err := httputil.DumpRequest(b.req, true)
+		if err != nil {
+			println(err.Error())
+		}
+		println(string(dump))
+	}
+
+	client := &http.Client{
+		Transport: &http.Transport{
+			Dial: TimeoutDialer(b.connectTimeout, b.readWriteTimeout),
+		},
+	}
+	resp, err := client.Do(b.req)
+	if err != nil {
+		return nil, err
+	}
+	return resp, nil
+}
+
+func (b *BeegoHttpRequest) String() (string, error) {
+	data, err := b.Bytes()
+	if err != nil {
+		return "", err
+	}
+
+	return string(data), nil
+}
+
+func (b *BeegoHttpRequest) Bytes() ([]byte, error) {
+	resp, err := b.getResponse()
+	if err != nil {
+		return nil, err
+	}
+	if resp.Body == nil {
+		return nil, nil
+	}
+	defer resp.Body.Close()
+	data, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	return data, nil
+}
+
+func (b *BeegoHttpRequest) ToFile(filename string) error {
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	resp, err := b.getResponse()
+	if err != nil {
+		return err
+	}
+	if resp.Body == nil {
+		return nil
+	}
+	defer resp.Body.Close()
+	_, err = io.Copy(f, resp.Body)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (b *BeegoHttpRequest) ToJson(v interface{}) error {
+	data, err := b.Bytes()
+	if err != nil {
+		return err
+	}
+	err = json.Unmarshal(data, v)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (b *BeegoHttpRequest) ToXML(v interface{}) error {
+	data, err := b.Bytes()
+	if err != nil {
+		return err
+	}
+	err = xml.Unmarshal(data, v)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (b *BeegoHttpRequest) Response() (*http.Response, error) {
+	return b.getResponse()
+}
+
+func TimeoutDialer(cTimeout time.Duration, rwTimeout time.Duration) func(net, addr string) (c net.Conn, err error) {
+	return func(netw, addr string) (net.Conn, error) {
+		conn, err := net.DialTimeout(netw, addr, cTimeout)
+		if err != nil {
+			return nil, err
+		}
+		conn.SetDeadline(time.Now().Add(rwTimeout))
+		return conn, nil
+	}
+}

httplib_test.go

+package beego
+
+import (
+	"io/ioutil"
+	"testing"
+)
+
+func TestGetUrl(t *testing.T) {
+	resp, err := GetUrl("http://beego.me/").Response()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if resp.Body == nil {
+		t.Fatal("body is nil")
+	}
+	data, err := ioutil.ReadAll(resp.Body)
+	defer resp.Body.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(data) == 0 {
+		t.Fatal("data is no")
+	}
+
+	str, err := GetUrl("http://beego.me/").String()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(str) == 0 {
+		t.Fatal("has no info")
+	}
+}