The Apache Solr server on the local computer can be started by running a java -jar start.jar command in Cygwin or cmd and closed by a Ctrl + C command. However, it's not convenient to manually check whether the Solr server is started, and an additional Cygwin or cmd window on the taskbar would be quite annoying. It's obviously a better design to do these via a few Java modules.
This post is a tutorial on how to start Solr server, close Solr server, and check whether the local Solr server is running or not by Java. I searched on the Internet, read some StackOverFlow posts, and wrote the code below. The three methods startSolrServer(), closeSolrServer(), and isSolrServerAlive() are responsible for the three functionalities respectively.
You can simply copy the three Java classes SyncPipe.java, LoggedPrintStream.java, and SolrUtilities.java below, paste them at some whether in your Java project, configure the solrDirectory, and directly use the three methods.
Beside, I feel that the design of the closeSolrServer() method is a bit inelegant. Weclome to leave comments below to provide better solutions about closing the Solr server by Java.
SyncPipe.java
package com.solrutils;
import java.io.InputStream;
import java.io.OutputStream;
public class SyncPipe implements Runnable {
public SyncPipe(InputStream istrm, OutputStream ostrm) {
istrm_ = istrm;
ostrm_ = ostrm;
}
public void run() {
try {
final byte[] buffer = new byte[1024];
for (int length = 0; (length = istrm_.read(buffer)) != -1;) {
ostrm_.write(buffer, 0, length);
}
} catch (Exception e) {
e.printStackTrace();
}
}
private final OutputStream ostrm_;
private final InputStream istrm_;
}
LoggedPrintStream.java
package com.solrutils;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintStream;
import java.lang.reflect.Field;
public class LoggedPrintStream extends PrintStream {
final StringBuilder buf;
final PrintStream underlying;
LoggedPrintStream(StringBuilder sb, OutputStream os, PrintStream ul) {
super(os);
this.buf = sb;
this.underlying = ul;
}
public static LoggedPrintStream create(PrintStream toLog) {
try {
final StringBuilder sb = new StringBuilder();
Field f = FilterOutputStream.class.getDeclaredField("out");
f.setAccessible(true);
OutputStream psout = (OutputStream) f.get(toLog);
return new LoggedPrintStream(sb, new FilterOutputStream(psout) {
public void write(int b) throws IOException {
super.write(b);
sb.append((char) b);
}
}, toLog);
} catch (NoSuchFieldException shouldNotHappen) {
} catch (IllegalArgumentException shouldNotHappen) {
} catch (IllegalAccessException shouldNotHappen) {
}
return null;
}
}
SolrUtilities.java
package com.solrutils;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
public class SolrUtilities {
private static final String solrDirectory = "D:/solr-4.1.0/";
public static void startSolrServer() {
try {
String[] command = { "cmd", };
Process p = Runtime.getRuntime().exec(command);
new Thread(new SyncPipe(p.getErrorStream(), System.err)).start();
new Thread(new SyncPipe(p.getInputStream(), System.out)).start();
PrintWriter stdin = new PrintWriter(p.getOutputStream());
stdin.println("cd /d D:");
stdin.println("cd " + solrDirectory + "example");
stdin.println("java -jar start.jar");
stdin.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static boolean isSolrServerAlive() {
try {
LoggedPrintStream lpsOut = LoggedPrintStream.create(System.out);
LoggedPrintStream lpsErr = LoggedPrintStream.create(System.err);
System.setOut(lpsOut);
System.setErr(lpsErr);
String[] command = { "cmd", };
Process p = Runtime.getRuntime().exec(command);
new Thread(new SyncPipe(p.getInputStream(), System.out)).start();
new Thread(new SyncPipe(p.getInputStream(), System.out)).start();
PrintWriter stdin = new PrintWriter(p.getOutputStream());
stdin.println("netstat -o -n -a | findstr 0:8983");
stdin.flush();
while (lpsOut.buf.lastIndexOf("findstr") == -1) {
System.out.println("lpsOut.buf = " + lpsOut.buf);
try {
Thread.sleep(250);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.setOut(lpsOut.underlying);
stdin.close();
if (lpsOut.buf.indexOf("LISTENING") == -1) {
return false;
} else {
return true;
}
} catch (Exception e) {
e.printStackTrace();
return false;
}
}
public static void closeSolrServer() {
try {
LoggedPrintStream lpsOut = LoggedPrintStream.create(System.out);
System.setOut(lpsOut);
String[] command = { "cmd", };
Process p = Runtime.getRuntime().exec(command);
new Thread(new SyncPipe(p.getErrorStream(), System.err)).start();
new Thread(new SyncPipe(p.getInputStream(), System.out)).start();
OutputStream outputStream = p.getOutputStream();
PrintWriter stdin = new PrintWriter(outputStream);
stdin.println("netstat -o -n -a | findstr 0:8983");
stdin.flush();
while (lpsOut.buf.lastIndexOf("findstr") == -1) {
try {
Thread.sleep(200);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.setOut(lpsOut.underlying);
if (lpsOut.buf.indexOf("LISTENING") == -1) {
System.err.println("SolrUtilities 62 the Solr server is already closed");
return;
} else {
String thePIDString = lpsOut.buf.substring(
lpsOut.buf.indexOf("LISTENING") + 9).trim();
int i = 0;
while (0 <= thePIDString.charAt(i) - '0'
&& thePIDString.charAt(i) - '0' <= 9)
i++;
thePIDString = thePIDString.substring(0, i);
stdin.println("taskkill /f /pid " + thePIDString);
}
stdin.close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void main(String[] args) {
boolean isSolrAlive = isSolrServerAlive();
System.out.println("SolrUtilities.main() 122 isSolrServerAlive? " + isSolrAlive);
if (!isSolrAlive) {
startSolrServer();
System.out.println("SolrUtilities.main() the Solr server is started");
}
try {
Thread.sleep(30000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
closeSolrServer();
System.out.println("SolrUtilities.main() the Solr server is closed");
}
}
