# homeWork2
###### tags: `Servlet`
java
```
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
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 HomeWork2
*/
@WebServlet("/HomeWork2")
public class HomeWork2 extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public HomeWork2() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html");
response.setCharacterEncoding("UTF-8");
PrintWriter out = response.getWriter();
// String user = request.getParameter("user");
// String password = request.getParameter("password");
out.println("<!DOCTYPE HTML>");
out.println("<html>");
out.println("<body>");
out.println(bodyContent(request.getReader()));
out.println("</body></html>");
}
private String bodyContent(BufferedReader reader) throws IOException{
String input = null;
StringBuilder requestBody = new StringBuilder();
while ((input = reader.readLine())!=null) {
requestBody.append(input)
.append("\n");
}
return requestBody.toString();
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
```
html
```
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Home Work 2</title>
</head>
<body>
<FORM ACTION="./HomeWork2" method="post">
使用者帳號:<INPUT TYPE="TEXT" NAME="user"><BR>
使用者密碼:<INPUT TYPE="password" NAME="password"><BR>
<CENTER>
<INPUT TYPE="SUBMIT">
</CENTER>
</FORM>
</body>
</html>
```
解法(去解碼)
```
private String bodyContent(BufferedReader reader) throws IOException{
String input = null;
StringBuilder requestBody = new StringBuilder();
while ((input = reader.readLine())!=null) {
requestBody.append(input)
.append("\n");
}
String text = java.net.URLDecoder.decode(requestBody.toString(), "UTF-8"); //解碼
return text;
}
```
```
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class HomeWork22
*/
@WebServlet(urlPatterns = {"/HomeWork22"},
initParams = {
// @WebInitParam(name = "name", value = "David"),
// @WebInitParam(name = "password", value = "a123456")
})
public class HomeWork22 extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public HomeWork22() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html");
response.setCharacterEncoding("UTF-8");
PrintWriter out = response.getWriter();
String name = request.getParameter("name");
String password= request.getParameter("password");
String user=getServletConfig().getInitParameter("name");
String pswd=getServletConfig().getInitParameter("password");
// PrintWriter writer = response.getWriter();
if (name.equals(user)&&password.equals(pswd)) {
out.println(name+"Hi !");
}else {
out.println("Error !!! ");
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
```
xml
```
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
<display-name>mywebdemo1</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>Homework22</servlet-name>
<servlet-class>Homework22</servlet-class>
<init-param>
<param-name>name</param-name>
<param-value>David</param-value>
</init-param>
<init-param>
<param-name>password</param-name>
<param-value>a123456</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>Homework22</servlet-name>
<url-pattern>/Homework22</url-pattern>
</servlet-mapping>
<context-param>
<param-name>ERROR</param-name>
<param-value>ERROR!!! 再輸入一次!</param-value>
</context-param>
</web-app>
```
html
```
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Home Work 22</title>
</head>
<body>
<FORM ACTION="./HomeWork22" method="post">
使用者帳號:<INPUT TYPE="TEXT" NAME="name" id="name"><BR>
使用者密碼:<INPUT TYPE="password" NAME="password" id="password"><BR>
<CENTER>
<INPUT TYPE="SUBMIT">
</CENTER>
</FORM>
</body>
</html>
```
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