上篇文章中，我们实现了C语言调用java方法，这次简单模拟AliPay支付流程。
- 首先是Activity的代码：
package com.shi.androidstudy.alipay;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
/**
* @anthor AFinalStone
* @email:602392033@qq.com
* @description: 简单模拟aliPay支付流程
* @time 2017/6/24 11:59
*/
public class MainActivity extends AppCompatActivity {
private EditText et_account, et_pwd, et_count;
private LinearLayout linearLayout_progressBar;
private TextView tv_msg;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 初始化控件
initViews();
}
private void initViews() {
et_account = (EditText) findViewById(R.id.et_account);
et_pwd = (EditText) findViewById(R.id.et_pwd);
et_count = (EditText) findViewById(R.id.et_count);
linearLayout_progressBar = (LinearLayout) findViewById(R.id.linearLayout_progressBar);
tv_msg = (TextView) findViewById(R.id.tv_msg);
}
public void onClick(View view) {
// 拿到数据
final String account = et_account.getText().toString().trim();
final String pwd = et_pwd.getText().toString().trim();
final int count = Integer.parseInt(et_count.getText().toString());
new Thread() {
@Override
public void run() {
// 调用C语言支付
int code = pay(account, pwd, count);
switch (code) {
case 0:
showMessage("支付成功");
break;
case 1:
showMessage("账号或者密码错误");
break;
case 2:
showMessage("金额超限");
break;
}
}
}.start();
}
private void showMessage(final String str) {
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(MainActivity.this, str, Toast.LENGTH_SHORT).show();
}
});
}
public void showProgressBar(final String msg) {
runOnUiThread(new Runnable() {
@Override
public void run() {
tv_msg.setText(msg);
linearLayout_progressBar.setVisibility(View.VISIBLE);
}
});
}
public void hideProgressBar() {
runOnUiThread(new Runnable() {
@Override
public void run() {
linearLayout_progressBar.setVisibility(View.GONE);
}
});
}
public static void println(String msg) {
System.out.println(msg);
}
public static String printlnAndBack(String msg) {
String backStr = "我是返回值:"+msg;
return backStr;
}
/**
* 账号 abc 密码 123
* @param account 账号
* @param pwd 密码
* @param count 支付金额
* @return 返回码 (0 支付成功)(1 账号或者密码错误)(2 金额超限 不能超过5000)
*/
public native int pay(String account, String pwd, int count);
static {
System.loadLibrary("alipay");
}
}然后是NDK代码
- alipay.c代码
#include <jni.h>
#include <stdio.h>
#include <stdlib.h>
#include <android/log.h>
#define LOG_TAG "System.out"
#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__)
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
char* Jstring2CStr(JNIEnv* env, jstring jstr) {
char* rtn = NULL;
jclass clsstring = (*env)->FindClass(env, "java/lang/String");
jstring strencode = (*env)->NewStringUTF(env, "GB2312");
jmethodID mid = (*env)->GetMethodID(env,clsstring, "getBytes", "(Ljava/lang/String;)[B");
jbyteArray barr = (jbyteArray)(*env)->CallObjectMethod(env,jstr,mid,strencode); // String.getByte("GB2312");
jsize alen = (*env)->GetArrayLength(env, barr);
jbyte* ba = (*env)->GetByteArrayElements(env, barr, JNI_FALSE);
if(alen > 0) {
rtn = (char*)malloc(alen+1); //"\0"
memcpy(rtn, ba, alen);
rtn[alen] = 0;
}
(*env) -> ReleaseByteArrayElements(env,barr,ba,0);
return rtn;
}
JNIEXPORT jint JNICALL Java_com_shi_androidstudy_alipay_MainActivity_pay
(JNIEnv *env, jobject obj, jstring account, jstring pwd, jint count) {
// 找到类com.shi.androidstudy.alipay.MainActivity
// jclass (*FindClass)(JNIEnv*, const char*);
jclass clazz = (**env).FindClass(env, "com/shi/androidstudy/alipay/MainActivity");
// 得到非静态方法 public void showProgressBar(final String msg)和public void hideProgressBar()
// jmethodID (*GetMethodID)(JNIEnv*, jclass 类, const char* 方法名, const char* 方法签名(需要使用javap获取方法签名;)返回类型);
jmethodID methodId_showProgressBar = (**env).GetMethodID(env, clazz, "showProgressBar", "(Ljava/lang/String;)V");
jmethodID methodId_hideProgressBar = (**env).GetMethodID(env, clazz, "hideProgressBar", "()V");
// 得到静态方法 public static void println(String msg)；
// jmethodID (*GetStaticMethodID)(JNIEnv*, jclass 类, const char* 方法名, const char* 方法签名(需要使用javap获取方法签名));
jmethodID methodId_println = (**env).GetStaticMethodID(env, clazz, "println", "(Ljava/lang/String;)V");
jmethodID methodId_printlnAndBack = (**env).GetStaticMethodID(env, clazz, "printlnAndBack", "(Ljava/lang/String;)Ljava/lang/String;");
// 调用获取到的方法
// void (*CallVoidMethod)(JNIEnv*, jobject, jmethodID, ...);
jstring msg =(*env)->NewStringUTF(env, "请稍等...");
(**env).CallVoidMethod(env, obj, methodId_showProgressBar, msg);
// 校验账号密码
LOGD("正在校验账号密码");
sleep(2);
// 验证登陆
LOGD("正在验证登陆");
sleep(2);
// 支付
LOGD("正在支付");
sleep(2);
(**env).CallVoidMethod(env, obj, methodId_hideProgressBar);
sleep(2);
//void (*CallStaticVoidMethod)(JNIEnv*, jclass 类, jmethodID 方法名, ...);
jstring tip =(*env)->NewStringUTF(env, "操作完成...");
(**env).CallStaticVoidMethod(env, clazz, methodId_println, tip);
//jobject (*CallStaticObjectMethod)(JNIEnv*, jclass, jmethodID, ...);
jstring tipBack = (**env).CallStaticObjectMethod(env, clazz, methodId_printlnAndBack, tip);
(**env).CallStaticVoidMethod(env, clazz, methodId_println, tipBack);
// 拿到C语言可以使用的字符串
char* pa = Jstring2CStr(env, account);
char* pp = Jstring2CStr(env, pwd);
// 定义正确的账号和密码
char* par = "abc";
char* ppr = "123";
// 判断字符串
int ia = strcmp(pa, par);
int ip = strcmp(pp, ppr);
if (ia == 0 && ip == 0) {
if (count > 5000) {
// 金额超限
return 2;
}
return 0;
} else {
// 账号密码错误
return 1;
}
}- Android.mk
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_LDLIBS += -llog
LOCAL_MODULE := alipay
LOCAL_SRC_FILES := alipay.c
include $(BUILD_SHARED_LIBRARY)编译NDK代码，生成.so文件，不要忘记修改gradle文件，指明.so文件的所在地。然后运行项目，看一下效果图
