package com.http.demo;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.ProtocolException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
/**
* http://www.cnblogs.com/not-NULL/p/5531866.html
* http://www.cnblogs.com/loveyakamoz/archive/2011/07/21/2113252.html
* HTTP工具
*/
public class HttpUtil {
/**
* 请求类型: GET
*/
public final static String GET = "GET";
/**
* 请求类型: POST
*/
public final static String POST = "POST";
/**
* HttpURLConnection方式 模拟Http Get请求
* @param urlStr请求路径
* @param paramMap 请求参数
*/
public static String get(String urlStr, Map<String, String> paramMap) throws Exception {
urlStr = urlStr + "?" + getParamString(paramMap);
HttpURLConnection conn = null;
try {
//创建URL对象
URL url = new URL(urlStr);
//获取URL连接
conn = (HttpURLConnection) url.openConnection();
//设置通用的请求属性
setHttpUrlConnection(conn, GET);
//建立实际的连接
conn.connect();
//获取响应的内容
return readResponseContent(conn.getInputStream());
} finally {
if (null != conn)
conn.disconnect();
}
}
/**
* HttpURLConnection方式 模拟Http Post请求
* @param urlStr请求路径
* @param paramMap请求参数
* @return
*/
public static String post(String urlStr, Map<String, String> paramMap) throws Exception {
HttpURLConnection conn = null;
PrintWriter writer = null;
try {
//创建URL对象
URL url = new URL(urlStr);
//获取请求参数
String param = getParamString(paramMap);
//获取URL连接
conn = (HttpURLConnection) url.openConnection();
//设置通用请求属性
setHttpUrlConnection(conn, POST);
//建立实际的连接
conn.connect();
//将请求参数写入请求字符流中
writer = new PrintWriter(conn.getOutputStream());
writer.print(param);
writer.flush();
//读取响应的内容
return readResponseContent(conn.getInputStream());
} finally {
if (null != conn)
conn.disconnect();
if (null != writer)
writer.close();
}
}
/**
* 读取响应字节流并将之转为字符串
* @param in要读取的字节流
*/
private static String readResponseContent(InputStream in) throws IOException {
Reader reader = null;
StringBuilder content = new StringBuilder();
try {
reader = new InputStreamReader(in);
char[] buffer = new char[1024];
int head = 0;
while ((head = reader.read(buffer)) > 0) {
content.append(new String(buffer, 0, head));
}
return content.toString();
} finally {
if (null != in)
in.close();
if (null != reader)
reader.close();
}
}
/**
* 设置Http连接属性
* @param connhttp连接
* @return
* @throws ProtocolException
* @throws Exception
*/
private static void setHttpUrlConnection(HttpURLConnection conn,
String requestMethod) throws ProtocolException {
conn.setRequestMethod(requestMethod);
conn.setRequestProperty("content-encoding", "utf8");
conn.setRequestProperty("accept", "application/json");
conn.setRequestProperty("Accept-Charset", "UTF-8");
conn.setRequestProperty("Accept-Language", "zh-CN");
conn.setRequestProperty("User-Agent",
"Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)");
conn.setRequestProperty("Proxy-Connection", "Keep-Alive");
System.out.println(conn.getRequestMethod());
if (null != requestMethod && POST.equals(requestMethod)) {
conn.setDoOutput(true);
conn.setDoInput(true);
}
}
/**
* 将参数转为路径字符串
* @param paramMap 参数
*/
private static String getParamString(Map<String, String> paramMap) {
if (null == paramMap || paramMap.isEmpty()) {
return "";
}
StringBuilder builder = new StringBuilder();
for (String key : paramMap.keySet()) {
builder.append("&").append(key).append("=").append(paramMap.get(key));
}
return new String(builder.deleteCharAt(0).toString());
}
public static void main(String[] args) {
String url = "http:www.baidu.com";
Map<String, String> params = new HashMap<>();
/*params.put("name", "jerry");
params.put("age", "18");
params.put("sex", "man");*/
try {
//System.out.println(post(url, params));
System.out.println(get(url,null));
} catch (Exception e) {
e.printStackTrace();
}
}
}
/** jar包依赖:
<!-- httpclient -->
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.3</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.3</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpmime</artifactId>
<version>4.3</version>
</dependency>
<dependency>
<groupId>org.apache.geronimo.bundles</groupId>
<artifactId>commons-httpclient</artifactId>
<version>3.1_2</version>
</dependency>
*/