1、只有查询
package webhandle;
import com.fasterxml.jackson.databind.ObjectMapper;
import utils.DbUtils;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.IOException;
/**
* Description :
*
* @author : HMF
* Date : Created in 16:38 2023/5/5
* @version :
*/
class Param {
public String sql;
}
@WebServlet("/api")
public class ApiDemo extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
resp.getWriter().write("Hello World!");
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("UTF-8");
String body=readBody(req);
//创建ObjectMapper对象,这个是Jackson中的核心类,
ObjectMapper objectMapper = new ObjectMapper();
//通过readvalue方法把body这个字符串转成JsonData对象
Param jsonData = objectMapper.readValue(body,Param.class);
//System.out.println(jsonData.sql);
String selSql=jsonData.sql;
DbUtils sd=new DbUtils();
String selectResult=sd.execSelect(selSql);
//返回结果数据
resp.setContentType("text/html;charset=utf-8");
resp.getWriter().write(selectResult);
}
private String readBody(HttpServletRequest req) throws IOException {
if(req.getMethod().equals("POST")){
StringBuilder result = new StringBuilder();
BufferedReader br = req.getReader();
String line;
while((line = br.readLine()) != null){
result.append(line);
}
br.close();
//System.out.println(result.toString());
return result.toString();
}
return null;
}
}
2、插入和查询
package webhandle;
import com.fasterxml.jackson.databind.ObjectMapper;
import utils.DbUtils;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.IOException;
/**
* Description :
*
* @author : HMF
* Date : Created in 16:38 2023/5/5
* @version :
*/
class Param {
public String sql;
}
@WebServlet("/api")
public class ApiDemo extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
resp.getWriter().write("Hello World!");
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("UTF-8");
String body=readBody(req);
//创建ObjectMapper对象,这个是Jackson中的核心类,
ObjectMapper objectMapper = new ObjectMapper();
//通过readvalue方法把body这个字符串转成JsonData对象
Param jsonData = objectMapper.readValue(body,Param.class);
//System.out.println(jsonData.sql);
String excSql=jsonData.sql;
DbUtils db=new DbUtils();
String excResult="";
if(excSql.contains("select")) {
excResult = db.execSelect(excSql);
}else{
int d=db.execOther(excSql);
if (d==1) {
excResult ="插入或更新成功";
}else{
excResult ="插入或更新失败,请检查";
}
}
//返回结果数据
resp.setContentType("text/html;charset=utf-8");
resp.getWriter().write(excResult);
}
private String readBody(HttpServletRequest req) throws IOException {
if(req.getMethod().equals("POST")){
StringBuilder result = new StringBuilder();
BufferedReader br = req.getReader();
String line;
while((line = br.readLine()) != null){
result.append(line);
}
br.close();
//System.out.println(result.toString());
return result.toString();
}
return null;
}
}