Java-->服务器的响应(Servlet--doGet&doPost)

--> Servelet: 用于接收请求(客户端,浏览器),做出响应的,服务器端的,java类

--> ServletLogin -- Web项目服务器响应的Java实现

package com.dragon.java.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
* Servlet implementation class ServletLogin
*/
@WebServlet("/ServletLogin")
public class ServletLogin extends HttpServlet {
private static final long serialVersionUID = 1L;

protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String user = parse(request.getParameter("user"));
String pwd = parse(request.getParameter("pwd"));
System.out.println(user + ":" + pwd);

response.setContentType("text/html;charset=utf-8");
PrintWriter writer = response.getWriter();
writer.println(user + "登陆成功!");
// 服务器会自动关流
}

protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8"); // 只解决post 请求乱码问题
doGet(request, response);
}

public String parse(String msg) throws UnsupportedEncodingException {
return new String(msg.getBytes("iso8859-1"), "utf-8");
}
}

1、doGet 方法：

--> HttpURLConnectionUtil 工具类

package com.dragon.java.urlbyget;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpURLConnectionUtil {
public static InputStream getInputStreamByGet(String url) {
try {
HttpURLConnection conn = (HttpURLConnection) new URL(url)
.openConnection();
conn.setRequestMethod("GET");
conn.setReadTimeout(10000);
conn.setConnectTimeout(10000);
// 用这个方法可以设置http的请求头
// conn.addRequestProperty("Accept", "......");

if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {
// 获取编码
// String contentType = conn.getContentType();
// String string = contentType.split("=")[1];

InputStream inputStream = conn.getInputStream();
return inputStream;
}
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}

--> Test 测试类

package com.dragon.java.urlbyget;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class Test {
public static void main(String[] args) {
InputStream inputStreamByGet = HttpURLConnectionUtil
.getInputStreamByGet("http://www.baidu.com");
try {
BufferedReader br = new BufferedReader(new InputStreamReader(
inputStreamByGet, "gb2312"));
String line = "";
while ((line = br.readLine()) != null) {
System.out.println(line);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}

----------------------------------邪恶的分割线------------------------------------

2、doPost 方法

--> HttpURLConnectionUtil 工具类

package com.dragon.java.urlbypost;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpURLConnectionUtil {
private static String charset;

public static InputStream getInputStreamByPost(String url, String parms) {
try {
HttpURLConnection conn = (HttpURLConnection) new URL(url)
.openConnection();
conn.setReadTimeout(5000);
conn.setConnectTimeout(5000);
conn.setRequestMethod("POST");

conn.setDoOutput(true);
OutputStream outputStream = conn.getOutputStream();
outputStream.write(parms.getBytes());
if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {
String contentType = conn.getContentType();
charset = contentType.split("=")[1];

InputStream inputStream = conn.getInputStream();
return inputStream;
}
} catch (IOException e) {
e.printStackTrace();
}
return null;
}

public static String getCharset() {
return charset;
}
}

--> InputStreamUtil 流到String的转换类

package com.dragon.java.urlbypost;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class InputStreamUtil {

public static String inputStreamToString(InputStream is, String charset) {
StringBuffer sb = new StringBuffer();
try (BufferedReader br = new BufferedReader(new InputStreamReader(is,
charset));) {
char[] buffer = new char[1024];
int len = -1;
while ((len = br.read(buffer)) != -1) {
sb.append(buffer, 0, len);
}
return sb.toString();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}

--> Test 测试类

package com.dragon.java.urlbypost;

import java.io.InputStream;

public class Test {
public static void main(String args[]) {

　　　　// 需要对URL中的中文参数进行编码。
　　　　String user = URLEncoder.encode("张三", "utf-8");
　　　　String pwd = URLEncoder.encode("你好", "utf-8");
　　　　InputStream inputStreamByPost = HttpURLConnectionUtil
　　　　　　　　.getInputStreamByPost(
　　　　　　　　　　　　"http://192.168.2.11:8080/08-23/ServletLogin", "user="
　　　　　　　　　　　　　　　　+ user + "&pwd=" + pwd);

System.out.println(InputStreamUtil.inputStreamToString(
inputStreamByPost, HttpURLConnectionUtil.getCharset()));
}
}

---> 注意先将Web项目导入到服务器并运行...