struts2 download file

Here’s a scenario:
1. User select a directory, and you show him all the files in that directory as ‘downloadable’
2. User select a file to download and gets it.

First, you need to write a Action class, that sends back a list of files in that directory.

public class MyAction extends ActionSupport{

	private List FilesList;
        public List getFilesList() {
		return FilesList;
	}

	public void setFilesList(List FilesList) {
		this.FilesList = FilesList;
	}
        
        public String files() throws Exception {
		String dirPath = (String) getGlobal(Constants.DIRPATH);
		File dir = new File(dirPath);

		ArrayList filesList = new ArrayList();
		String[] children = dir.list();
		if (children == null) {
			// Either dir does not exist or is not a directory
		} else {
			for (int i = 0; i < children.length; i++) {
				// Get filename of file or directory
				String filename = children[i];
				File file = new File(dirPath + File.separator + filename);
				Files files= new Files();
				files.setFileSize(readableFileSize(file.length()));
				files.setFileName(filename);
				filesList.add(files);
			}
		}

		setFilesList(filesList);
		return Constants.SUCCESS;
	}
}

Your JSP needs to have this listing:

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s" uri="/struts-tags"%>

<s:if test="%{filesList!=null && filesList.size > 0}">
    <table border=0 cellspacing=1 cellpadding=1 width=60% align=center	class=tablebody>
	<s:iterator value="filesList" status="rownum">
	    <tr height=25>
		<td align=left style='font-family: verdana; font-size: 11pt' nowrap>
                    <s:url id="fileDownload" action="download">
			<s:param name="downloadFileName" value="{fileName}" />
		    </s:url> 
                    <s:a href="%{fileDownload}"><s:property value="fileName" /></s:a> 
                    <span style="font-family: verdana; font-size: 9pt"><s:property value="fileSize" /></span>
                </td>
	    </tr>
	</s:iterator>
</table>
</s:if>
<s:else test="%{filesList!=null && filesList.size == 0}">
			No files found
</s:else>

Couple of interesting things in the struts tags above:

<s:url id="fileDownload" action="download">
	<s:param name="downloadFileName" value="{fileName}" />
</s:url> 
<s:a href="%{fileDownload}"><s:property value="fileName" /></s:a> 

This specifying a URL with the parameter as the selected filename. If you want to see the filename being apprended to the URL,You can specify includeParams="get" to s:url.

Now, lets map the ‘download’ action in struts.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>

	<constant name="struts.devMode" value="true" />

	<package name="basicstruts2" extends="struts-default">

		<interceptors>
			<interceptor-stack name="appDefaultStack">
				<interceptor-ref name="defaultStack">
					<param name="exception.logEnabled">true</param>
					<param name="exception.logLevel">ERROR</param>
				</interceptor-ref>
			</interceptor-stack>
		</interceptors>

		<default-interceptor-ref name="appDefaultStack" />

		<default-action-ref name="input" />

		<global-results>
			<result name="error">/error.jsp</result>
		</global-results>

		<global-exception-mappings>
			<exception-mapping exception="java.lang.Exception"
				result="error" />
		</global-exception-mappings>



		<action name="input"
			class="com......"
			method="prepare">
			<result name="success">/....jsp</result>
		</action>

		<action name="*Filter"
			class="com......"
			method="{1}">
			<result name="success">/.....jsp</result>
			<result name="error">/error.jsp</result>
			<result name="input">/mdt_viewer.jsp</result>
		</action>

		
		<action name="download" class="com.action.DownloadAction"
			method="download">
			<result name="success" type="stream">
				<param name="contentType">application/zip</param>
				<param name="inputName">fileInputStream</param>
				<!--param name="contentDisposition">attachment;filename="fileABC.txt"</param -->
				<param name="bufferSize">1024</param>
			</result>
		</action>
	</package>

</struts>

Lets check out the DownloadAction class,

public class DownloadAction extends ActionSupport{
	private InputStream fileInputStream;
	private String downloadFileName;

        /**
	 * Will override the default in struts.xml. 
	 * 
	 * @return
	 */
	public String getContentDisposition() {
		return "attachment;filename=" + getDownloadFileName();
	}

       
        	public InputStream getFileInputStream() {
		return fileInputStream;
	}

	public void setFileInputStream(InputStream fileInputStream) {
		this.fileInputStream = fileInputStream;
	}

	public String getDownloadFileName() {
		return downloadFileName;
	}

	public void setDownloadFileName(String downloadFileName) {
		this.downloadFileName = downloadFileName;
	}


        public String download() throws Exception {
		log.debug("Fetching for download:" + getDownloadFileName());
		String filesPath = (String) getGlobal(Constants.DIR_PATH);

		try {
			String file = filesPath 
					+ File.separator + getDownloadFileName();
			setFileInputStream(new FileInputStream(file));
			return Constants.SUCCESS;
		} catch (Exception e) {
			log.error(e);
			throw e;
		}
	}
}

Thats about it! Happy downloading.

Quick copy/paste for Java connecting to Oracle

package com.xerox.remsvcs.utils;

import java.sql.Array;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.Timestamp;
import java.sql.Types;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;

import oracle.jdbc.driver.OracleCallableStatement;
import oracle.jdbc.driver.OracleTypes;
import oracle.sql.ARRAY;

public class Connecttooracle {

	private static Connection getConn() {
		Connection connection = null;
		try {
			// Load the JDBC driver
			String driverName = "oracle.jdbc.OracleDriver";
			Class.forName(driverName);

			// Create a connection to the database
			String serverName = "127.0.0.1";
			String portNumber = "1521";
			String sid = "mydatabase";
			String url = "jdbc:oracle:thin:@<IP>:1521:<DB>";
			String username = "";
			String password = "1234";
			connection = DriverManager.getConnection(url, username, password);
		} catch (Exception e) {
			e.printStackTrace();
		}

		return connection;
	}

	

	public static void mai(String[] args) {
		String sql = "";

		Connection connection = getConn();
		PreparedStatement cstmt = null;
		ResultSet rs = null;
		List<String> serialNoList = new ArrayList<String>();
		long start = System.currentTimeMillis();
		try {

			cstmt = connection.prepareCall(sql);
			rs = cstmt.executeQuery();
			System.out.println("execute=" + (System.currentTimeMillis() - start));
			start = System.currentTimeMillis();
			while (rs.next()) {
			

			}
			System.out.println("snolist=" + (System.currentTimeMillis() - start));

			System.out.println(serialNoList);
			System.out.println(serialNoList.size());
		} catch (Exception e) {
			e.printStackTrace();

		} finally {
			closeConnections(connection, cstmt, null);
		}

	}

	public static void main(String[] args) {
		String sql = "{call ABC.XX_lib.GetName(?,?,?,?)}";
		Connection connection = getConn();
		CallableStatement cstmt = null;
		ResultSet rs = null;
		List<String> serialNoList = new ArrayList<String>();
		long start = System.currentTimeMillis();
		try {

			cstmt = (CallableStatement) connection.prepareCall(sql);
			cstmt.setString(1, "121332");
			cstmt.setString(2, "2232222");
			cstmt.setString(3, "www");

			cstmt.registerOutParameter(4, OracleTypes.CURSOR);
			cstmt.execute();
			System.out.println("execute=" + (System.currentTimeMillis() - start));
			start = System.currentTimeMillis();
			rs = (ResultSet) cstmt.getObject(4);
			while (rs.next()) {
				serialNoList.add((String) (rs.getString("timestamp")));
			}
			System.out.println("snolist=" + (System.currentTimeMillis() - start) + ","
					+ serialNoList.size());

			System.out.println(serialNoList);
		} catch (Exception e) {
			e.printStackTrace();

		} finally {
			closeConnections(connection, cstmt, null);
		}

	}

	public static void closeConnections(Connection conn, Statement stmt, ResultSet rs) {
		try {
			if (rs != null) {
				rs.close();
			}
			if (stmt != null) {
				stmt.close();
			}
			if (conn != null) {
				conn.close();
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

Ant script to create a WAR file

<?xml version="1.0"?>
<project name="MyWebPortal" default="deploy" basedir=".">
	<description>
           MyWeb Portal
    </description>

	<property name="src.dir" value="src/main/java" />
	<property name="test.dir" value="src/test/java" />
	<property name="lib.dir" value="src/main/lib" />
	<property name="resources.dir" value="src/main/resources" />
	<property name="build.dir" value="build" />
	<property name="dist.dir" value="dist" />
	<property name="webapps.dir" value="src/main/webapps" />
	<property name="app.name" value="MyWebPortal" />
	<property name="deploy.dir" value="\\jboss-5.1.0.GA\\server\\default\\deploy" />


	<target name="clean" description="Delete old build and dist directories">
		<delete dir="${dist.dir}" />
		<delete dir="${build.dir}" />
	</target>

	<target name="init" depends="clean" description="Create build directory">
		<mkdir dir="${build.dir}" />
		<mkdir dir="${dist.dir}" />
	</target>

	<target name="compile" depends="init" description="Compile Java sources">
		<mkdir dir="${build.dir}/WEB-INF/classes" />
		<echo message="Using Java version ${ant.java.version}."/>
		<javac srcdir="${src.dir}" destdir="${build.dir}/WEB-INF/classes" debug="true"  
	          source="1.6" target="1.6">
			<classpath>
				<path>
					<fileset dir="${lib.dir}" />
				</path>
			</classpath>
		</javac>

	</target>


	<target name="build" depends="compile" description="Copies all non Java classes to build directoy">
		<copy todir="${build.dir}/WEB-INF/classes">
			<fileset dir="${resources.dir}" includes="struts.xml,struts.properties" />
		</copy>
		<copy todir="${build.dir}">
			<fileset dir="${resources.dir}" excludes="struts.xml,log4j.*,*-ds.xml" />
		</copy>
		<copy todir="${build.dir}/WEB-INF/lib">
			<fileset dir="${lib.dir}" excludes="jboss-common-jdbc-wrapper.jar,ojdbc*.jar"/>
		</copy>
		<copy todir="${build.dir}/WEB-INF">
			<fileset dir="${webapps.dir}/WEB-INF" excludes="SVN,**/*.class" />
		</copy>
		<copy todir="${build.dir}/META-INF">
			<fileset dir="${webapps.dir}/META-INF" />
		</copy>
		<copy todir="${build.dir}">
			<fileset dir="${webapps.dir}" includes="**/*.jsp,**/*.htm" />
		</copy>
	</target>


	<target name="archive" depends="build" description="Create binary archive of all files in dist.home">

		<!-- Create application WAR file -->
		<jar jarfile="${dist.dir}/${app.name}.war" basedir="${build.dir}" />

	</target>

	<target name="deploy" depends="archive">
		<copy todir="${deploy.dir}">
			<fileset dir="${dist.dir}" includes="${app.name}.war" />
		</copy>

	</target>
</project>

Java calling PL/SQL proc returning a TYPE

Take this piece of code:

Connection connection = getConn();
		CallableStatement cstmt = null;
		List serialList = new ArrayList();
		try {

			cstmt = (CallableStatement) connection.prepareCall(sql);
			cstmt.registerOutParameter(1, Types.ARRAY, "tblXYZNum".toUpperCase());
			cstmt.execute();
			Array arr = cstmt.getArray(1);
			String[] serialNumbers = (String[])arr.getArray();
			System.out.println(serialNumbers);
			System.out.println(serialNoList);

Few things that need notice:
1. The TYPE name has to be in upper case.
2. The TYPE shouldnt be declared inside a PL/SQL package. It should have been created as ‘CREATE TYPE’. Java does not have access to TYPE’s inside a package. You will get an invalid name pattern error if you refer a TYPE inside a package.

Kill multiple unix processes

ps -ef | grep <process_name> | cut -d' ' -f3 | awk '{x=x" "$1} END {print x}'

Kill multiple oracle sessions

SELECT  'alter system kill session '''||sess.SID||','|| sess.serial# ||''';'
FROM v$session sess, v$sql SQL
WHERE sql.sql_id(+) = sess.sql_id
AND sess.type = 'USER'
AND sql.sql_text like 'XYZ%';

I didnt find any other way. Executing the above SQL, will give a bunch of Alter statements.