Integrated Windows local application to eclipse RCP program

Windows applications are very rich, and sometimes some of the features required by our Eclipse RCP programs already have implementations of existing Windows local applications that we want to be able to reuse in our RCP programs. One of the easiest ways to reuse it is to embed the local application window directly in our RCP window. To enable a Windows local application to run in our RCP program, we can use the reparent mechanism provided by Windows. The main process for window embedding using this mechanism is to start the Windows program embedded in our program first, then try to get the main window handle after the program starts, and then set our RCP program's window to the parent window of the Windows Program's main window.

Since we need to start the Windows local program and get its main window handle, these can only be implemented using a Windows local call, so we first use Windows Local invocation to implement the corresponding functionality, and then we invoke it in JNI.

Introduction to JNI

The full name of JNI is the Java Native Interface,jni Standard is part of the Java platform that interacts with code written in Java code and in other languages. Here's a quick introduction to the steps to use JNI:

Writing a Java method with native declarations

Here take HelloWorld as an example:

Listing 1. Hello World Java Code

public　class　HelloWorld　{
　 static　{
　 System.loadLibrary(“helloworld”)}
　 }

　 public　native　void　print()}

　 public　static　void　main(String[]　args)　{
　 HelloWorld　hello　=　new　HelloWorld()}
　 hello.print()}
　 }
}

Compiling Java code and generating a C + + header file:

First compile this Java class: Javac Helloworld.java, and then generate a header file with an. h extension, Java provides a command Javah to generate the header file: Javah–jni HelloWorld, the following list shows the contents of the generated header file:

Listing 2. Hello World C + + header file

/*　DO　NOT　EDIT　THIS　FILE　-　it　is　machine　generated　*/
#include　<jni.h>}
/*　Header　for　class　HelloWorld　*/

#ifndef　_Included_HelloWorld
#define　_Included_HelloWorld
#ifdef　__cplusplus
extern　"C"　{
#endif
/*
　 *　Class:　　　HelloWorld
　 *　Method:　　print
　 *　Signature:　()V
　 */
JNIEXPORT　void　JNICALL　Java_HelloWorld_print　(JNIEnv　*,　jobject)}

#ifdef　__cplusplus
}
#endif
#endif