java学习笔记(2)

　　这几天过年呆家各种串门，被搞得半死，不过平常有空还是看看java，现在把这几天学习的东西总结一下，主要是javaWEB的代码：

　　javaWEB的servlet是容器， webRoot(webContent)这个目录是服务器对外的根目录，这个目录下的所有文件都可以通过web直接访问，这个目录也就是我们常说的VIEW（视图层）；

　　如果我们新建了servlet，如何新建一个servlet可以参考这里， eclipse会自动新建一个指向该servlet的映射， servlet默认会引入几个java文件

//这个很重要
import java.io.PrintWriter;
//IO异常和servlet异常
import java.io.IOException;
import javax.servlet.ServletException;
//annotation是声明的意思;
import javax.servlet.annotation.WebServlet;
//
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

　　@WebServlet(description = "test0", urlPatterns = { "/test0" }) ；这句话的意思是所有访问 /test0 的patterns，都会调用这个servlet;

　　@WebServlet(name = "controllerServlet", urlPatterns = {"/product_input", "/product_save"})；这句话的意思是所有访问 /product_input, /product_save 的patterns，都会调用这个servlet, 在这个servlet里面直接判断url然后对每一种地址做对应的返回，这个就是controller(控制器) ;

　　MVC现在还差Model了， Model就是数据层面的增删改查，根据用户的操作（GET，POST或者其他请求方式）我们返回对应的Model给用户，

　　新建出来的servlet.java文件默认有 doGet， doPost，还有init 以及destory等默认的实例公用非法，init方法里面可以放初始化的代码，没有为空就可以了，比如：

    public void init() throws ServletException {
    	london = new ArrayList<String>(10);
    	paris = new ArrayList<String>(10);
    	london.add("buckingham palace");
    	london.add("london Eye");
    	london.add("British Museum");
    	london.add("national Gallery");
    	
    	paris.add("Eiffel Tower");
    	paris.add("notre Dame");
    	paris.add("the louvre");
    	paris.add("champs elysees");
    }

　　doGet或者doPost的两个参数分别为HttpServletRequest request, HttpServletResponse response；

　　HttpServletRequest 有这些方法：

1:getAuthType
2:getCookies
3:getDateHeader
4:getHeader
5:getHeaderNames
6:getIntHeader
7:getMethod
8:getPathInfo
9:getPathTranslated
10:getQueryString
11:getRemoteUser
12:getRequestedSessionId
13:getRequestURL
14:getServletPath
15:getSession
16:isRequestedSessionIdValid

　　HttpServletResponse的方法

flushBuffer
getBufferSize
getCharacterEncoding
getContentType
getLocale
getOutputStream
getWriter
isCommitted
reset
resetBuffer
setBufferSize
setCharacterEncoding
setContentLength
setContentType
setLocale
addHeader
sendError
sendError
setHeader
setStatus
addCookie

　　一个doGet返回的简单例子：

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		response.setContentType("text/html");
		PrintWriter writer = response.getWriter();
		writer.write( "<form method='post'>" +
				"<table>"+
					"<tr>" +
						"<td>" +
							"<select name='titleFontSize'>" +
								"<option>large</option>" +
								"<option>xlarge</option>" +
								"<option>xxlarge</option>" +
							"</select>" +
						"</td>" +
						"<td><input type='submit' value='set' /></td>" +
					"</tr>" +
				"</table>" +
				"</form>" );
		writer.flush();
		writer.close();
		
	}

　　提供一个例子大概了解了javaBean是什么东东，有两个模型（UserBean.java 和 UserCheckBean.java), login.jsp. loginchk.jsp两个jsp文件：

　　UserBean.java

package user.model;

public class UserBean {
    private String name;
    private String password;
    
    public String getName () {
        return this.name;
    }
    public void setName( String name ) {
        this.name = name;
    }
    public String getPassword() {
        return this.password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
}

　　UserCheckBean.java

package user.model;

public class UserCheckBean {
	protected UserBean user;
	public UserCheckBean () {
		
	}
	public UserCheckBean( UserBean user ) {
		this.user = user;
	}
	public UserBean getUser () {
		return user;
	}
	public void setUser( UserBean user ){
		this.user = user;
	}
	public boolean validate() {
		String name = user.getName();
		String password = user.getPassword();
		if( "x".equals(name) && "x".equals(password) ) {
			return true;
		}else{
			return false;
		}
	}
}

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
    <form method="POST" action="longinchk.jsp">
        name : <input type="text" name="name" />
        password : <input type="text" name="password" />
        <input type="submit" value="submit" />
    </form>
</body>
</html>

　　loginchk.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
    <!-- 
        因为eclipse会自动检测错误， 引用路径错误了会自动提示错误等， 没有写js那样，要各种调试， 都不知道哪里错误了;
     -->
<%@ page import="user.model.UserCheckBean" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
    <%
        request.setCharacterEncoding("GB2312");
    %>
    <jsp:useBean id="user" scope="session" class="user.model.UserBean" />
    <jsp:setProperty name="user" property="*" />
    
    <%
        UserCheckBean uc = new UserCheckBean( user );
    if( uc.validate() ) {
　　　　out.println("登陆成功");

    } else {
        out.println("wrong user or wrong password!");
    }
    %>
</body>

</html>

　　还有一个javaBean的例子，包括一个javabean文件，一个reg.html和reg.jsp,显示用户信息的userInfo.jsp：

　　bean.java

package beans;
import java.io.Serializable;

public class bean implements Serializable{
	private String name;
	private int sex;
	private String education;
	private String email;
	
	public String getName () {
		return this.name;
	}
	public void setName(String name) {
		this.name = name;
	}
	
	public int getSex() {
		return this.sex;
	}
	public void setSex( int sex ) {
		this.sex = sex;
	}
	
	public String getEducation() {
		return this.education;
	}
	public void setEducation( String education ) {
		this.education = education;
	}
	
	public String getEmail () {
		return this.email;
	}
	public void setEmail (String email) {
		this.email = email;
	}
}

　　reg.html;

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
    <form action="reg.jsp" method="post" >
        <div>
            name : <input name="name" />
        <div>
            sex :   <input type="radio" name="sex" value="1"/>男
                    <input type="radio" name="sex" value="0"/>女
        <div>
            eduction : 
            <select type="" name="education">
                <option value="高中">高中</option>
                <option value="大学">大学</option>
                <option value="硕士">硕士</option>
                <option value="博士">博士</option>
            </select>        
        <div>
            email : <input name="email" />
        </div>
        <div>
            <input type="submit" value="submit"/>
        </div>
    </form>
</body>
</html>

　　reg.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%
	request.setCharacterEncoding("GB2312");
%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
	<jsp:useBean id="user" scope="session" class="beans.bean" />
	<jsp:setProperty name="user" property="*" />
	注册成功
</body>
</html>

　　userInfo.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
	<jsp:useBean id="user" scope="session" type="beans.bean"></jsp:useBean>
	你的姓名<jsp:getProperty name="user" property="name" /> </br>
	你的性别<%
		int sex = user.getSex();
		if( 1 == sex ) {
			out.println("男");
		}else{
			out.println("女");
		};
	%></br>
	你的学历<jsp:getProperty name="user" property="education" /></br>
	<%
		out.println( user.getEducation() );
	%>
	你的email<jsp:getProperty name="user" property="email" />
</body>
</html>

posted @ 2015-02-22 20:41 方方和圆圆阅读(264) 评论(0) 收藏举报

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方方和圆圆

你好世界，哈罗，开普勒452b

java学习笔记(2)

公告

方方和圆圆

你好世界， 哈罗， 开普勒452b

java学习笔记(2)

公告

你好世界，哈罗，开普勒452b