java接口接受json

Question

public class Crtl extends HttpServlet {

    private static Log log = LogFactory.getLog(WacaiRemoteRequest.class);
    private static ObjectMapper objectMapper = new ObjectMapper();
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=utf-8");
        //这里需要接受调用者传过来的json参数
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        doGet(req, resp);
    }
}

写一个接口给别人调用，我需要接收到调用者传过来的json然后转换为list，再去调用另一个接口返回结果，请问怎样接收json？

Answer 1

package com.sample.servlet;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.IOException;

public class SampleHttpServlet extends HttpServlet {

    private static final long serialVersionUID = -2074707407667590820L;

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doGet(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        //用于接收对方的jsonString
        StringBuilder jsonString = new StringBuilder();
        BufferedReader reader = req.getReader();
        try {
            String line;
            while ((line = reader.readLine()) != null) {
                jsonString.append(line).append('\n');
            }
        } finally {
            reader.close();
        }
        //doYourThings(jsonString.toString())  继续做你的业务就可以了
    }
}

Answer 2

json转换成字符串提交，后台再转换成json

Answer 3

为什么不用map接收呢

Answer 4

import java.io.IOException;
import java.io.StringWriter;
import java.util.Map;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.framework.exception.BusinessException;

public class JsonUtils{
    
  private static final ObjectMapper mapper = new ObjectMapper();

  /**
   * json转换成map
   * @author layson
   * @param json
   * @return
   * @throws BusinessException
   */
  public static Map<?, ?> json2Map(String json)throws BusinessException{
    Map result = null;
    try {
      result = (Map)mapper.readValue(json, Map.class);
    } catch (IOException e) {
      e.printStackTrace();
      throw new BusinessException(-1, "Json转换成Map时出现异常。", e);
    }
    return result;
  }

}