用JSP实现学生查询
前两天学习Servlet时，用Servlet做了一个小小个学生查询功能，现在学习了JSP就用JSP来实现这个小功能。
首先新建一个JSP文件student.jsp,代码如下：
1 <%@ page language=”java” contentType=”text/html;charset=GB2312” %>
2 <%@ page import=”java.sql.Timestamp”%>
3 <%@ page import=”java.text.“%>
4 <%@ page import=”java.util.“%>
5 <%@ page import=”com.pojo.“%>
6 <%@ page import=”com.services.“%>
7
8
9
10
11
12
13 出生日期：至
14
15
16 <%
17 String sBeginDate = request.getParameter(“begindate”);
18 String sEndDate = request.getParameter(“enddate”);
19 //将字符串转换为Timestamp
20 Timestamp beginDate = Timestamp.valueOf(“1900-1-1 00:00:00”);
21 Timestamp endDate = Timestamp.valueOf(“1900-1-1 00:00:00”);
22 try{
23 beginDate = Timestamp.valueOf(sBeginDate+” 0:0:0”);
24 endDate = Timestamp.valueOf(sEndDate+” 0:0:0”);
25 }catch(Exception e){
26 e.printStackTrace();
27 }
28 StudentService ss = new StudentService();
29 //从数据库中查询结果
30 List l = ss.getStudentByDate(beginDate,endDate);
31 %>
32 <%
33 if(l.size()!= 0 && l!=null){
34 %>
35
36
37
38
39
40
41
42
43 <%
44for(Iterator iter=l.iterator();iter.hasNext();){
45 Student s = iter.next();
46 %>
47
48
49
50
51
52
53
54 <%}%>
55
学号 姓名 出生日期 性别 家庭住址
<%=s.getSId()%> <%=s.getSName()%> <%=new SimpleDateFormat(“yyyy-MM-dd”).format(s.getSDate())%> <%=s.getSSex()%> <%=s.getSAddr()%>
56 <%
57 }
58 %>
59
60 再把相应的业务逻辑jar包和数据库驱动拷贝到lib目录下。
编译后的student_jsp.java代码如下：
1 package org.apache.jsp;
2
3 import javax.servlet.;
4 import javax.servlet.http.;
5 import javax.servlet.jsp.;
6 import java.sql.Timestamp;
7 import java.text.;
8 import java.util.;
9 import com.pojo.;
10 import com.services.*;
11
12 public final class student_jsp extends org.apache.jasper.runtime.HttpJspBase
13 implements org.apache.jasper.runtime.JspSourceDependent {
14
15 private static final JspFactory _jspxFactory = JspFactory.getDefaultFactory();
16
17 private static java.util.List _jspx_dependants;
18
19 private javax.el.ExpressionFactory _el_expressionfactory;
20 private org.apache.AnnotationProcessor _jsp_annotationprocessor;
21
22 public Object getDependants() {
23 return _jspx_dependants;
24 }
25
26 public void _jspInit() {
27 _el_expressionfactory = _jspxFactory.getJspApplicationContext(getServletConfig().getServletContext()).getExpressionFactory();
28 _jsp_annotationprocessor = (org.apache.AnnotationProcessor) getServletConfig().getServletContext().getAttribute(org.apache.AnnotationProcessor.class.getName());
29 }
30
31 public void _jspDestroy() {
32 }
33
34 public void _jspService(HttpServletRequest request, HttpServletResponse response)
35 throws java.io.IOException, ServletException {
36
37 PageContext pageContext = null;
38 HttpSession session = null;
39 ServletContext application = null;
40 ServletConfig config = null;
41 JspWriter out = null;
42 Object page = this;
43 JspWriter _jspx_out = null;
44 PageContext _jspx_page_context = null;
45
46
47 try {
48 response.setContentType(“text/html;charset=GB2312”);
49 pageContext = _jspxFactory.getPageContext(this, request, response,
50 null, true, 8192, true);
51 _jspx_page_context = pageContext;
52 application = pageContext.getServletContext();
53 config = pageContext.getServletConfig();
54 session = pageContext.getSession();
55 out = pageContext.getOut();
56 _jspx_out = out;
57
58 out.write(“\r\n”);
59 out.write(“\r\n”);
60 out.write(“\r\n”);
61 out.write(“\r\n”);
62 out.write(“\r\n”);
63 out.write(“\r\n”);
64 out.write(“\r\n”);
65 out.write(“\t\r\n”);
66 out.write(“\t\t\r\n”);
67 out.write(“\t\r\n”);
68 out.write(“\t\r\n”);
69 out.write(“\t\t
\r\n”);
70 out.write(“\t\t\t出生日期：至\r\n”);
71 out.write(“\t\t\t\r\n”);
72 out.write(“\t\t
\r\n”);
73 out.write(“\t\t”);
74
75 String sBeginDate = request.getParameter(“begindate”);
76 String sEndDate = request.getParameter(“enddate”);
77 //将字符串转换为Timestamp
78 Timestamp beginDate = Timestamp.valueOf(“1900-1-1 00:00:00”);
79 Timestamp endDate = Timestamp.valueOf(“1900-1-1 00:00:00”);
80 try{
81 beginDate = Timestamp.valueOf(sBeginDate+” 0:0:0”);
82 endDate = Timestamp.valueOf(sEndDate+” 0:0:0”);
83 }catch(Exception e){
84 e.printStackTrace();
85 }
86 StudentService ss = new StudentService();
87 //从数据库中查询结果
88 List l = ss.getStudentByDate(beginDate,endDate);
89
90 out.write(“\r\n”);
91 out.write(“\t\t”);
92
93 if(l.size()!= 0 && l!=null){
94
95 out.write(“\r\n”);
96 out.write(“\t\t\r\n”);
97 out.write(“\t\t\t\r\n”);
98 out.write(“\t\t\t\t\r\n”);
99 out.write(“\t\t\t\t\r\n”);
100 out.write(“\t\t\t\t\r\n”);
101 out.write(“\t\t\t\t\r\n”);
102 out.write(“\t\t\t\t\r\n”);
103 out.write(“\t\t\t\r\n”);
104 out.write(“\t\t\t”);
105
106for(Iterator iter=l.iterator();iter.hasNext();){
107 Student s = iter.next();
108
109 out.write(“\r\n”);
110 out.write(“\t\t\t\r\n”);
111 out.write(“\t\t\t\t\r\n”);
114 out.write(“\t\t\t\t\r\n”);
117 out.write(“\t\t\t\t\r\n”);
120 out.write(“\t\t\t\t\r\n”);
123 out.write(“\t\t\t\t\r\n”);
126 out.write(“\t\t\t\r\n”);
127 out.write(“\t\t\t”);
128}
129 out.write(“\r\n”);
130 out.write(“\t\t
学号 姓名 出生日期 性别 家庭住址
“);
112 out.print(s.getSId());
113 out.write(“ “);
115 out.print(s.getSName());
116 out.write(“ “);
118 out.print(new SimpleDateFormat(“yyyy-MM-dd”).format(s.getSDate()));
119 out.write(“ “);
121 out.print(s.getSSex());
122 out.write(“ “);
124 out.print(s.getSAddr());
125 out.write(“
\r\n”);
131 out.write(“\t\t”);
132
133 }
134
135 out.write(“\r\n”);
136 out.write(“\t\r\n”);
137 out.write(““);
138 } catch (Throwable t) {
139 if (!(t instanceof SkipPageException)){
140 out = _jspx_out;
141 if (out != null && out.getBufferSize() != 0)
142 try { out.clearBuffer(); } catch (java.io.IOException e) {}
143 if (_jspx_page_context != null) _jspx_page_context.handlePageException(t);
144 }
145 } finally {
146 _jspxFactory.releasePageContext(_jspx_page_context);
147 }
148 }
149 }
相比Servlet,JSP的实现简单了许多，在JSP文件中HTML语句可以直接写，不需要拼凑。