jni example

with the javah command, you can enter javah-help. -O -D -V-verbose enables detailed output-H -- help -? Output this message-Version: Output version information.-Jni: generate a JNI-style header file (default)-Force always writes the input file-Classpath Path introduction:E: \ android-sdks \ platforms \Android-23\ Android. jar is the sdk version that the android project depends on and is eventually locked

1. JNI JNI is the abbreviation of Java Native Interface. Java Native Interface (JNI) standards have become part of the java platform since Java1.1. It allows Java code to interact with code written in other languages. JNI was initially designed for locally compiled languages, especially C and C ++, but it does not pre

Recent projects in JNI, as a result of the first use, have looked up some information and are summarized as follows:Resources:1, http://docs.oracle.com/javase/6/docs/technotes/guides/jni/index.html2, http://blog.csdn.net/fightspirite/article/details/68598293, http://blog.csdn.net/super005/article/details/63875754, http://www.cr173.com/html/17867_1.html5, http://www.cnblogs.com/codc-5117/archive/2012/09/06/2

Introduction to Android JNI and androidjniJNI Introduction JNI (Java Native Interface), a local Java Interface JNI is one of the many Java development technologies. It is intended to use local code to provide more efficient and flexible expansion for Java programs. Application scenarios include: Implementation of algorithms that are sensitive to operational effic

/lang/String; String jstringLjava/net/Socket; Socket jobject If a JAVA function is located in an embedded class, $ is used as the delimiter between class names. For example, "(Ljava/lang/String; Landroid/OS/FileUtils $ FileStatus;) Z" With the above knowledge, you will understand the relationship between the native method and the data type between java.In addition, for jni development, the native method nam

to compile c/c ++ code. Let's take a look at how to compile the code. First, we will create a jni folder in the android project, create a C-language source file in the jni folder, and wear a class in android, class, you can use the native identifier to create a function. For example: public class DataProvider {// the C language with parameters calls java public

Due to the working relationship, JNI must be used to call methods and transmit data between C ++ and Java programs. However, JNI used to work in an English environment and is encoded in Chinese (similar to other languages) I am not paying much attention to the problem. I recently took some time to study it and sorted out my experiences as follows for your discussion or reference.Before further discussion, w

Preface When testing the availability of the tinythread ++ library on different mobile platforms, several problems were encountered. Tinythread ++ is known as a thread library compatible with the c ++ 11 standard. It can be used when C ++ 11 is unavailable. In the future, C ++ 11 will become more popular and can be easily replaced. Test status on different platforms: IOS: Pass. You need to rename the. M file that calls the C ++ code to the. MM file. WP: unknown. Not involved. Android: Pass.

QtAndroid details (4): JNI calls Android system functions (1), qtandroidjni In the previous sections, we have explained the basic usage of the QtAndroid namespace. This time, we will use the methods and class libraries we mentioned earlier to demonstrate some simple small examples. In my book Qt on Android core programming, I mainly call some Android functions by inheriting QtActivity, implementing my own Activity and adding static methods. In this se

JNI is an interface between Java and C/s + + programming, which makes it easy to implement Java calls to C + + languages. Specific use methods, there are many tutorials on the Internet, do not do too much introduction. This blog only focuses on common issues in the process of using JNI.1. Generate header file with command: Javah*.classThis is wrong. Running the above command prompts: Java.lang.IllegalArgume

QtAndroid (4): JNI calls Android system functions (1) In the previous sections, we have explained the basic usage of the QtAndroid namespace. This time, we will use the methods and class libraries we mentioned earlier to demonstrate some simple small examples. In my book Qt on Android core programming, I mainly call some Android functions by inheriting QtActivity, implementing my own Activity and adding static methods. In this series of articles, we m

Android JNI-learning notes, androidjniGetting started with JNI-learning notes Executable File Windows -*. exe | linux -*. elfc function library file Windows -*. dll | linux -*. so batch file Windows -*. bat | linux -*. shTools NDK -- native developer kits Cygwin-Linux System Simulator Installation Process key points: -- can be installed online during installation or through a local file (if there is a loc

Java Native Interface (JNI) is a bridge between Java and C/s + +. In some cases, to improve the performance of Java programs and extend the functionality of Java programs, we need to use JNI. For example, when we download a JDBC jar package, we can see the dynamic link library containing the different platforms in the database: This article describes how to crea

simply need to modify the Mk file (stating "which files need to compile", "compilation characteristics Requirements", etc.), you can create a so.The NDK can automatically package so with Java applications, greatly reducing the developer's packaging effort.Second, NDK Construction of bad environment:Note: At present has been out of ndk-r9b, because the author wrote this log when the download is still ndk-r8c, so still take ndk-r8c as an example to exp

The previous article introduces the use of JNI in Android using a simple example. This article is based on the understanding that some Java parameter types differ from the local parameter types. 1) The return value in Java is completely corresponding to void in JNI. (just one). 2) basic data types in Java (byte, short, int,long,float,double, boolean,char

dependent on the project to java. library. path of the java project. Generate a java program Publish java applications and so libraries. Let's just say that the domestic materials are really poor. I used wikipedia's JNI entry and my own practice to write this blog .. P.S and later, we must work harder to learn English ~~ Http://en.wikipedia.org/wiki/Java_Native_Interface Below is a simple example of Hel

the annoying things are managed by a thread called GC (when an object is not referenced by other objects, the object will be released by GC ). However, I think the internal memory management principle of Java is very similar to that of C/C ++. In the above example, Animal cat = new Cat ("Tom "); the local variable cat is stored in the stack space, new Cat ("Tom"); The created instance object is stored in the heap space, and a reference to the memory

Problem description: When calling DLL using JNI, you must first generate the DLL file Solution: (1.exe now use the cl.exe program of vs2008to generate the DLL file (1.1)cl.exe environment setup Note: The location of the cl.exe program is in the VC \ bin directory of the VS installation directory. When you directly run the preceding program, the program automatically exits. The correct method is to add Include, path, and lib paths to the syste

The construction process of JNI development applications on Android is basically the same. The following describes the construction process of jni apk Based on the surfaceview function of JNI layer painting on Android. APK directory structure: ├── AndroidManifest.xml├── Android.mk├── jni│ ├── Android.mk│ ├── logger.