I am working on a java program where I have to call another java program using process builder because it uses a separate JRE.
Here is batch program which calls this program and works properly:
cd C:\apps\Project_name\bin\
C:\Progra~1\Java\jre1.6.0_03\bin\java -Xms512m -Xmx1024m
-cp ../lib/spring-1.2.2.jar;../lib/log4j-1.2.8.jar;../lib/commons-logging-1.0.4.jar;../lib/wrapper.jar
com.project.main.MainProgramLauncher arg1 arg2
Now I declared my code something like this:
ProcessBuilder builder = new ProcessBuilder(
"java",
"-Xms512m",
"-Xmx1024m",
"-cp ../lib/spring-1.2.2.jar;../lib/log4j-1.2.8.jar;"+
"../lib/commons-logging-1.0.4.jar;../lib/wrapper.jar",
"com.project.main.MainProgramLaunche开发者_如何学Pythonr arg1 arg2 ...argN"
);
Map<String, String> environment = builder.environment();
environment.put("path", ";"); // Clearing the path variable;
environment.put("path", java_bin_location+";");
Process javap = builder.start();
InputStreamReader tempReader = new InputStreamReader(
new BufferedInputStream(javap.getInputStream())
);
BufferedReader reader = new BufferedReader(tempReader);
while (true) {
String line = reader.readLine();
if (line == null)
break;
System.out.println(line);
}
But its not executing the way it should be. The program crashing right away. Is there anything different I should be doing? Please suggest.
I'm guessing that you should make your class name and parameters different strings. instead of:
"java",
"-Xms512m",
"-Xmx1024m",
"-cp ../lib/spring-1.2.2.jar;../lib/log4j-1.2.8.jar;"+
"../lib/commons-logging-1.0.4.jar;../lib/wrapper.jar",
"com.project.main.MainProgramLauncher arg1 arg2 ...argN"
It should be
"java",
"-Xms512m",
"-Xmx1024m",
"-cp",
"../lib/spring-1.2.2.jar;../lib/log4j-1.2.8.jar;"+
"../lib/commons-logging-1.0.4.jar;../lib/wrapper.jar",
"com.project.main.MainProgramLauncher",
"arg1",
"arg2",
...
"argN"
The other noticeable thing that you used the full path name to call java.exe
, but not when you used ProcessBuilder
.
You might also want to read the error stream (or call redirectErrorStream(true)
- the argument is important(!)).
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