我想在Openshift上创建使用Tomcat，Spring和Hibernate的Web应用程序。
首先，我尝试使用像此
这样的persistence.xml配置数据库<?xml version="1.0" encoding="UTF-8"?> <persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0">
<persistence-unit name="springshop_pu" transaction-type="RESOURCE_LOCAL"> <provider>org.hibernate.ejb.HibernatePersistence</provider>
<class>com.codeonblue.springshop.model.Categoria</class>
<class>com.codeonblue.springshop.model.Produto</class>
<class>com.codeonblue.springshop.model.Usuario</class> <properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect" />
<property name="hibernate.hbm2ddl.auto" value="update"/>
<property name="hibernate.show_sql" value="true" />
<property name="hibernate.format_sql" value="true"/> <property name="hibernate.connection.charset" value="UTF-8" />
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
#{systemEnvironment[OPENSHIFT_MYSQL_DB_HOST]}
<property name="javax.persistence.jdbc.user" value="#{systemEnvironment[OPENSHIFT_MYSQL_DB_USERNAME]}"/>
<property name="javax.persistence.jdbc.password" value="#{systemEnvironment[OPENSHIFT_MYSQL_DB_PASSWORD]}"/>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://#{systemEnvironment[OPENSHIFT_MYSQL_DB_HOST]}:#{systemEnvironment[OPENSHIFT_MYSQL_DB_PORT]}/#{systemEnvironment[OPENSHIFT_APP_NAME]}"/>
</properties>
使用以下内容但是当我尝试创建 EntityManagerFactory 时，我收到此错误：
java.lang.NumberFormatException: For input string: "#{systemEnvironment[OPENSHIFT_MYSQL_DB_PORT]}"
后来我尝试修改我的persistence.xml，如下所示：
<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0">
<persistence-unit name="springshop_pu" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<class>com.codeonblue.springshop.model.Categoria</class>
<class>com.codeonblue.springshop.model.Produto</class>
<class>com.codeonblue.springshop.model.Usuario</class>
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect" />
<property name="hibernate.hbm2ddl.auto" value="update"/>
<property name="hibernate.show_sql" value="true" />
<property name="hibernate.format_sql" value="true"/>
<property name="hibernate.connection.charset" value="UTF-8" />
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property name="javax.persistence.jdbc.user" value="${env.OPENSHIFT_MYSQL_DB_USERNAME}"/>
<property name="javax.persistence.jdbc.password" value="${env.OPENSHIFT_MYSQL_DB_PASSWORD}"/>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://${env.OPENSHIFT_MYSQL_DB_HOST}:${env.OPENSHIFT_MYSQL_DB_PORT}/${env.OPENSHIFT_APP_NAME}"/>
</properties>
</persistence-unit>
</persistence>
但我有这个错误：
java.sql.SQLException: Must specify port after ':' in connection string
在我看来，openshift数据库变量为null。
这是我进行测试的servlet：
@WebServlet("/GenerateTables")
public class GenerateTables extends HttpServlet {
private static final long serialVersionUID = 1L;
public GenerateTables() {
super();
// TODO Auto-generated constructor stub
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
System.out.println("Host: " + System.getenv("OPENSHIFT_MYSQL_DB_HOST"));
System.out.println("Port: " + System.getenv("OPENSHIFT_MYSQL_DB_PORT"));
System.out.println("Username: " + System.getenv("OPENSHIFT_MYSQL_DB_USERNAME"));
System.out.println("Password: " + System.getenv("OPENSHIFT_MYSQL_DB_PASSWORD"));
EntityManagerFactory factory = Persistence
.createEntityManagerFactory("springshop_pu");
factory.close();
System.out.println("Let's see if the tables were generated");
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
}
然而，这个命令在servlet中
System.out.println("Host: " + System.getenv("OPENSHIFT_MYSQL_DB_HOST"));
System.out.println("Port: " + System.getenv("OPENSHIFT_MYSQL_DB_PORT"));
System.out.println("Username: " + System.getenv("OPENSHIFT_MYSQL_DB_USERNAME"));
System.out.println("Password: " + System.getenv("OPENSHIFT_MYSQL_DB_PASSWORD"));
显示Tomcat日志中的变量值
我在这里做错了什么？
请帮帮我
答案 0 :(得分：0)
我放弃了使用openshift环境变量。我放弃了项目并从头再次开始，但这次我使用了openshift提供的预先配置的上下文（MySQLDS）并且完美地工作。
首先我在数据库中插入了一些数据：
--
-- Table structure for table `names`
--
CREATE TABLE IF NOT EXISTS `names` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`first` varchar(50) NOT NULL,
`last` varchar(50) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=5 ;
--
-- Data for table `names`
--
INSERT INTO `names` (`id`, `first`, `last`) VALUES
(1, 'John', 'Doe'),
(2, 'Jane', 'Doe'),
(3, 'John', 'Smith'),
(4, 'Jane', 'Smith');
然后我创建了文件 mysql.jsp ，如下所示：
<%@ page language="java" contentType="text/html; charset=US-ASCII" pageEncoding="US-ASCII"%>
<%@ page import='java.sql.*' %>
<%@ page import='javax.sql.*' %>
<%@ page import='javax.naming.*' %>
<!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=US-ASCII">
<title>Tomcat 6 & Tomcat 7 (JBOSS EWS) Example</title>
</head>
<body>
<%
Connection result = null;
try {
InitialContext ic = new InitialContext();
Context initialContext = (Context) ic.lookup("java:comp/env");
DataSource datasource = (DataSource) initialContext.lookup("jdbc/MySQLDS");
result = datasource.getConnection();
Statement stmt = result.createStatement() ;
String query = "select * from names;" ;
ResultSet rs = stmt.executeQuery(query) ;
while (rs.next()) {
out.println(rs.getString(1) + " " + rs.getString(2) + " " + rs.getString(3) + "<br />");
}
} catch (Exception ex) {
out.println("Exception: " + ex + ex.getMessage());
}
%>
</body>
</html>
上面的代码效果非常好。
如果有人想要更多细节，请按照此链接中的说明操作： https://help.openshift.com/hc/en-us/articles/202399720-How-to-use-the-pre-configured-MySQLDS-and-PostgreSQLDS-data-sources-in-the-Java-cartridges
希望能帮助别人。
干杯！