读取包内的属性配置文件
package demo;
import java.util.ResourceBundle;
public class Main
{
public static void main(String[] args)
{
ResourceBundle res = ResourceBundle.getBundle("demo/App");
System.out.print(res.getString("DB_PATH"));
}
}
Tomcat 的连接池配置
- 在tomcat的server.xml 中的 GlobalNamingResources 节点之间添加如下代码
- <Resource name="jdbc/bbs" type="javax.sql.DataSource" driverClassName="sun.jdbc.odbc.JdbcOdbcDriver" url="jdbc:odbc:driver={Microsoft Access Driver (*.mdb)};DBQ=D:\\bbs.mdb"/>
- 在当前项目的 META-INF/context.xml 的 context 节点之间添加如下代码
- <ResourceLink name="jdbc/bbs" global="jdbc/bbs" type="javax.sql.DataSourcer"/>
- 在程序中用这样的方式获得连接
- javax.naming.Context ctx = new javax.naming.InitialContext();
- javax.sql.DataSource ds =(DataSource)ctx.lookup("java:comp/env/jdbc/bbs");
- java.sql.Connection conn = ds.getConnection();
- 将2中的代码直接写到项目的context.xml中也可以
Struts 2的配置
- 将struts2的jar文件添加到项目的lib文件夹
- 在项目的web.xml 中的 web-app 节点之间添加如下代码
- <display-name>Struts Blank</display-name>
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
- <display-name>Struts Blank</display-name>
- 在package 根目录添加 package.properties
- 在默认 package 添加 struts.xml 代码如下 配置Action的跳转映射
- <struts>
<package name="tutorial" extends="struts-default">
<action name="HelloWorld" class="tutorial.HelloWorld">
<result name="success">HelloWorld.jsp</result>
<result name="error">HelloWorldErr.jsp</result>
<result name="input">SayHello.jsp</result>
</action>
</package>
</struts>
- <struts>
HelloWorld.java
package tutorial;import com.opensymphony.xwork2.ActionSupport;public class HelloWorld extends ActionSupport
{
private String name; private String message; public void setName(String name)
{ this.name = name;
} public String getMessage() { return message; } @Override public String execute() { if(this.name.equals("")) { return INPUT; } if(this.name.equals("wengmj")) { this.message=getText("HELLO.SUCCESS",new String[]{this.name}); return SUCCESS; } else { this.message=getText("HELLO.ERROR",new String[]{this.name}); return ERROR; } }
}HelloWorld.jsp
<%@ taglib prefix="s" uri="/struts-tags" %><html> <head> <title>Hello</title> </head> <body> <h3><s:property value="message" /></h3> </body></html>
Java 的可变参数方法定义，类似于C#的 params object[] args
public class Main
{
public static void main(String[] args)
{
say("hello","+","world");
}
public static void say(String args)
{
StringBuffer sb = new StringBuffer();
for(String s:args)
sb.append(s);
System.out.print(sb.toString());
//out:hello+world
}
}
javax.servlet.http.Cookie c = new javax.servlet.http.Cookie("name", "wengmj");
response.addCookie(c);
name = request.getCookies()[0].getValue();
package summer;
import java.sql.*;
public class Main {
public static void main(String args[]) throws SQLException
{
DriverManager.registerDriver(new oracle.jdbc.OracleDriver());
Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@192.168.201.153:1521:TESTDB", "dangdang", "dangdang");
Statement stmt = conn.createStatement();
ResultSet rset = stmt.executeQuery("select * from com_review where rownum<10");
while (rset.next())
System.out.println(rset.getString(1));
}
}
package jDang.sql;
import java.io.BufferedReader;
import java.io.Reader;
import java.sql.Clob;
public class DBUtil
{
public static String readClob(Clob clob)
{
try
{
Reader reader = clob.getCharacterStream();
BufferedReader br = new BufferedReader(reader);
String s;
StringBuffer sb = new StringBuffer();
while ((s = br.readLine()) != null)
sb.append(s);
br.close();
reader.close();
return sb.toString();
}
catch (Exception e)
{
return e.getMessage();
}
}
}
变量作用域有 page request session application ， EL 的不带隐式对象前缀直接访问变量的搜索顺序就是这个顺序，也可以用
xxxScope.变量名 来精确定位的访问。
pageScope.xxx 的变量在pageContext中设置，
变量作用域是要有一个作用域容器的。page作用域变量要和页面局部变量和页面类域变量区别。