Request_获取请求参数通用方式演示和Request_获取请求参数中文乱码问题处理

String getparamter(String name) :根据参数名获取参数值，    username=zs &password=123

@WebServlet("/requestDemo1")
public class requestDemo1 extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String username = req.getParameter("username");
        System.out.println("get");
        System.out.println(username);

    }


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


       /* String username = req.getParameter("username");
        System.out.println("post");
        System.out.println(username);*/

        this.doPost(req,resp);
    }

 

String[] getParametervalue（String name）：根据参数名获取参数值的数组  hobby=xx&hobby=game

@WebServlet("/requestDemo1")
public class requestDemo1 extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String username = req.getParameter("username");

        String[] hobbies = req.getParameterValues("hobby");
        for (String hobby : hobbies) {
            System.out.println(hobby);
        }

    }

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

 

 

 

 

 

 

Enumeration<String> getParamterNames() 获取所有请求的参数名称

@WebServlet("/requestDemo1")
public class requestDemo1 extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String username = req.getParameter("username");
        Enumeration<String> parameterNames = req.getParameterNames();
        while (parameterNames.hasMoreElements()){
            String name = parameterNames.nextElement();
            System.out.println(name);
            String parameter = req.getParameter(name);
            System.out.println(parameter);
            System.out.println("-----------");
        }

    }

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

map<String,String[]> getParamter():获取所有参数的map结合

 

@WebServlet("/requestDemo1")
public class requestDemo1 extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String username = req.getParameter("username");
        Map<String, String[]> parameterMap = req.getParameterMap();
        Set<String> set = parameterMap.keySet();
        for (String s : set) {
            String[] strings = parameterMap.get(s);
            System.out.println(s);
            for (String string : strings) {
                System.out.println(string);
            }
            System.out.println("--------------------------");
        }

    }


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

        this.doPost(req,resp);
    }

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Request_获取请求参数中文乱码问题处理

 

中文乱码问题：

　　　get方式：tomcat 8 已经将get方式乱码问题解决了

　　　post方式：会乱码

　　　　　解决：在获取参数前，设置request的编码request.setCharacterEncoding("utf-8");

 

@WebServlet("/requestDemo2")
public class requestDemo2 extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        String username = req.getParameter("username");
        System.out.println(username);
    }
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req,resp);
    }
}

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