servlet接收json以及返回json

• 方法一：

package com.test;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.PrintWriter;

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

public class TestsServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        this.doPost(request, response);

    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        response.setContentType("application/json");
        response.setCharacterEncoding("UTF-8");
        request.setCharacterEncoding("UTF-8");

        /**
         * 接收json
         */
        BufferedReader reader = request.getReader();
        String json = reader.readLine();
        System.out.println(json);
        reader.close();

        /**
         * 返回json
         */
        PrintWriter out = response.getWriter();
        out.write("{\"name\":\"舞蹈家\"}");
        out.close();

    }

}

• 方法二：

package com.test;

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

import javax.servlet.ServletException;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class TestsServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        this.doPost(request, response);

    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        response.setContentType("application/json");
        response.setCharacterEncoding("UTF-8");
        request.setCharacterEncoding("UTF-8");

        /**
         * 接收json
         */
        BufferedReader br = new BufferedReader(new InputStreamReader(
                (ServletInputStream) request.getInputStream(), "utf-8"));
        StringBuffer sb = new StringBuffer("");
        String temp;
        while ((temp = br.readLine()) != null) {
            sb.append(temp);
        }
        br.close();
        System.out.println(sb.toString());


        /**
         * 返回json
         */
        // 转成数据流
        InputStream is = new ByteArrayInputStream(
                "{\"name\":\"账单\"}".getBytes());
        // 输出到画面
        ServletOutputStream op = response.getOutputStream();
        int len;
        byte[] buff = new byte[4096];
        while ((len = is.read(buff)) != -1) {
            op.write(buff, 0, len);
        }
        op.flush();

    }

}