事件处理（Event Handling）

优质

小牛编辑

127浏览

2023-12-01

在本文中，我们将演示如何使用JDBC在JSF中集成数据库。

以下是运行此示例的数据库要求。

S.No	软件和描述
1	PostgreSQL 9.1 开源和轻量级数据库
2	PostgreSQL JDBC4驱动程序 PostgreSQL 9.1和JDK 1.5或更高版本的JDBC驱动程序

将PostgreSQL JDBC4驱动程序jar放在tomcat web服务器的lib目录中。

Database SQL Commands

create user user1;
create database testdb with owner = user1;
CREATE TABLE IF NOT EXISTS authors (
    id int PRIMARY KEY, 
    name VARCHAR(25)
);
INSERT INTO authors(id, name) VALUES(1, 'Rob Bal');
INSERT INTO authors(id, name) VALUES(2, 'John Carter');
INSERT INTO authors(id, name) VALUES(3, 'Chris London');
INSERT INTO authors(id, name) VALUES(4, 'Truman De Bal');
INSERT INTO authors(id, name) VALUES(5, 'Emile Capote');
INSERT INTO authors(id, name) VALUES(7, 'Breech Jabber');
INSERT INTO authors(id, name) VALUES(8, 'Bob Carter');
INSERT INTO authors(id, name) VALUES(9, 'Nelson Mand');
INSERT INTO authors(id, name) VALUES(10, 'Tennant Mark');
alter user user1 with password 'user1';
grant all on authors to user1;

例子 Example Application

让我们创建一个测试JSF应用程序来测试JDBC集成。

步	描述
1	在cn.xnip.test包下创建一个名为helloworld的项目，如JSF - First Application一章中所述。
2	在src → main文件夹下创建resources文件夹。
3	在src → main → resources文件夹下创建css文件夹。
4	在src → main → resources → css文件夹下创建styles.css文件。
5	修改styles.css文件，如下所述。
6	修改pom.xml ，如下所述。
7	在Author.java包下创建Author.java ，如下所述。
8	在包cn.xnip.test下创建UserData.java ，如下所述。
9	修改home.xhtml ，如下所述。保持其余文件不变。
10	编译并运行应用程序以确保业务逻辑按照要求运行。
11	最后，以war文件的形式构建应用程序并将其部署在Apache Tomcat Webserver中。
12	使用适当的URL启动Web应用程序，如下面的最后一步所述。

styles.css

.authorTable {   
   border-collapse:collapse;
   border-bottom:1px solid #000000;
}
.authorTableHeader {
   text-align:center;
   background:none repeat scroll 0 0 #B5B5B5;
   border-bottom:1px solid #000000;
   border-top:1px solid #000000;
   padding:2px;
}
.authorTableOddRow {
   text-align:center;
   background:none repeat scroll 0 0 #FFFFFFF;	
}
.authorTableEvenRow {
   text-align:center;
   background:none repeat scroll 0 0 #D3D3D3;
}

pom.xml

<project xmlns = "http://maven.apache.org/POM/4.0.0" 
   xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation = "http://maven.apache.org/POM/4.0.0
   http://maven.apache.org/maven-v4_0_0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <groupId>cn.xnip.test</groupId>
   <artifactId>helloworld</artifactId>
   <packaging>war</packaging>
   <version>1.0-SNAPSHOT</version>
   <name>helloworld Maven Webapp</name>
   <url>http://maven.apache.org</url >
   <dependencies>
      <dependency>
         <groupId>junit</groupId>
         <artifactId>junit</artifactId>
         <version>3.8.1</version>
         <scope>test</scope>
      </dependency>
      <dependency>
         <groupId>com.sun.faces</groupId>
         <artifactId>jsf-api</artifactId>
         <version>2.1.7</version>
      </dependency>
      <dependency>
         <groupId>com.sun.faces</groupId>
         <artifactId>jsf-impl</artifactId>
         <version>2.1.7</version>
      </dependency>
      <dependency>
         <groupId>javax.servlet</groupId>
         <artifactId>jstl</artifactId>
         <version>1.2</version>
      </dependency>
      <dependency>
        <groupId>postgresql</groupId>
        <artifactId>postgresql</artifactId>
        <version>9.1-901.jdbc4</version>
     </dependency>
   </dependencies>
   <build>
      <finalName>helloworld</finalName>
      <plugins>
         <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>2.3.1</version>
            <configuration>
               <source>1.6</source>
               <target>1.6</target>
            </configuration>
         </plugin>
         <plugin>
            <artifactId>maven-resources-plugin</artifactId>
            <version>2.6</version>
            <executions>
               <execution>
                  <id>copy-resources</id>
                  <phase>validate</phase>
                  <goals>
                     <goal>copy-resources</goal>
                  </goals>
                  <configuration>
                     <outputDirectory>${basedir}/target/helloworld/resources
                        </outputDirectory>
                     <resources>          
                        <resource>
                           <directory>src/main/resources</directory>
                           <filtering>true</filtering>
                        </resource>
                     </resources>              
                  </configuration>            
               </execution>
            </executions>
         </plugin>
      </plugins>
   </build>
</project>

Author.java

package cn.xnip.test;
public class Author {
   int id;
   String name;
   public String getName() {
      return name;
   }
   public void setName(String name) {
      this.name = name;
   }
   public int getId() {
      return id;
   }
   public void setId(int id) {
      this.id = id;
   }
}

UserData.java

package cn.xnip.test;
import java.io.Serializable;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.faces.event.ComponentSystemEvent;
@ManagedBean(name = "userData", eager = true)
@SessionScoped
public class UserData implements Serializable {
   private static final long serialVersionUID = 1L;
   public List<Author> getAuthors() {
      ResultSet rs = null;
      PreparedStatement pst = null;
      Connection con = getConnection();
      String stm = "Select * from authors";
      List<Author> records = new ArrayList<Author>();
      try {   
         pst = con.prepareStatement(stm);
         pst.execute();
         rs = pst.getResultSet();
         while(rs.next()) {
            Author author = new Author();
            author.setId(rs.getInt(1));
            author.setName(rs.getString(2));
            records.add(author);				
         }
      } catch (SQLException e) {
         e.printStackTrace();
      }
      return records;
   }
   public Connection getConnection() {
      Connection con = null;
      String url = "jdbc:postgresql://localhost/testdb";
      String user = "user1";
      String password = "user1";
      try {
         con = DriverManager.getConnection(url, user, password);
         System.out.println("Connection completed.");
      } catch (SQLException ex) {
         System.out.println(ex.getMessage());
      }
      finally {
      }
      return con;
   }
}

home.xhtml

<?xml version = "1.0" encoding = "UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns = "http://www.w3.org/1999/xhtml"
   xmlns:f = "http://java.sun.com/jsf/core"    
   xmlns:h = "http://java.sun.com/jsf/html">
   <h:head>
      <title>JSF Tutorial!</title>
      <h:outputStylesheet library = "css" name = "styles.css"  /> 
   </h:head>
   <h:body>
      <h2>JDBC Integration Example</h2>
      <h:dataTable value = "#{userData.authors}" var = "c"
         styleClass = "authorTable"
         headerClass = "authorTableHeader"
         rowClasses = "authorTableOddRow,authorTableEvenRow">
         <h:column><f:facet name = "header">Author ID</f:facet>
            #{c.id}
         </h:column>
         <h:column><f:facet name = "header">Name</f:facet>
            #{c.name}
         </h:column>
      </h:dataTable>
   </h:body>
</html>

一旦准备好完成所有更改，让我们像在JSF - First Application章节中那样编译和运行应用程序。如果您的应用程序一切正常，这将产生以下结果。