#include <string.h>
#include <jni.h>
/* This is a trivial JNI example where we use a native method
* to return a new VM String. See the corresponding Java source
* file located at:
*
* apps/samples/hello-jni/project/src/com/example/hellojni/HelloJni.java
*/
jstring
Java_com_example_hellojni_HelloJni_stringFromJNI( JNIEnv* env,
jobject thiz )
{
return (*env)->NewStringUTF(env, "Hello from JNI !");
}
jstring
Java_com_example_hellojni_strtojstring(JNIEnv* env,jobject thiz, const char *ptr)
{
//定义一个java string class
jclass strclass=(env)->Findclass("Ljava/lang/String;");
//获取String(byte[],String)的构造器,用于将本地byte[]数组转换为一个新String
jmethodID strmethod=(env)->GetMethodID(strclass, "<init>", "([BLjava/lang/String;)V");
//建立byte数组
jbyteArray bytes = (env)->NewByteArray(strlen(ptr));
//将char* 转换为byte数组
(env)->SetByteArrayRegion(bytes, 0, strlen(ptr), (jbyte*)ptr);
// 设置String, 保存语言类型,用于byte数组转换至String时的参数
jstring encoding = (env)->NewStringUTF("GB2312");
//将byte数组转换为java String,并输出
return (jstring)(env)->NewObject(strclass, strmethod, bytes, encoding);
}
std::string jstring2str(JNIEnv* env, jstring jstr)
{
char* rtn=NULL;
jclass clsstring=env->FindClass("java/lang/String");
jstring strencode=env->NewStringUTF("GB2312");
jmethodID mid=env->GetMethodID(clsstring, "getBytes", "(Ljava/lang/String;)[B");
jbyteArray barr=(jbyteArray)env->CallObjectMethod(jstr,mid,strencode);
jsize alen=env->GetArrayLength(barr);
jbyte* ba=env->GetByteArrayElements(barr,JNI_FALSE);
if(alen>0)
{
rtn = (char*)malloc(alen+1);
memcpy(rtn,ba,alen);
rtn[alen]=0;
}
env->ReleaseByteArrayElements(barr,ba,0);
std::string stemp(rtn);
free(rtn);
return stemp;
}
//jstring to char*
char* jstringTostring(JNIEnv* env, jstring jstr)
{
char* rtn = NULL;
jclass clsstring = env->FindClass("java/lang/String");
jstring strencode = env->NewStringUTF("utf-8");
jmethodID mid = env->GetMethodID(clsstring, "getBytes", "(Ljava/lang/String;)[B");
jbyteArray barr= (jbyteArray)env->CallObjectMethod(jstr, mid, strencode);
jsize alen = env->GetArrayLength(barr);
jbyte* ba = env->GetByteArrayElements(barr, JNI_FALSE);
if (alen > 0)
{
rtn = (char*)malloc(alen + 1);
memcpy(rtn, ba, alen);
rtn[alen] = 0;
}
env->ReleaseByteArrayElements(barr, ba, 0);
return rtn;
}
//char* to jstring
jstring stoJstring(JNIEnv* env, const char* pat)
{
jclass strClass = env->FindClass("Ljava/lang/String;");
jmethodID ctorID = env->GetMethodID(strClass, "", "([BLjava/lang/String;)V");
jbyteArray bytes = env->NewByteArray(strlen(pat));
env->SetByteArrayRegion(bytes, 0, strlen(pat), (jbyte*)pat);
jstring encoding = env->NewStringUTF("utf-8");
return (jstring)env->NewObject(strClass, ctorID, bytes, encoding);
}
//invoke function
JNIEXPORT jstring JNICALL
Java_test_cs_web_SWIFTAlianceCASmfTest_strcal(JNIEnv *env, jclass obj, jstring jstr1, jstring jstr2)
{
jbyteArray bytes = 0;
jthrowable exc;
char *pszResult = NULL;
char *pszSTR1 = NULL;
char *pszSTR2 = NULL;
pszSTR1 = jstringTostring(env, jstr1);
pszSTR2 = jstringTostring(env, jstr2);
int nlen = sizeof(char)*(strlen(pszSTR1)+strlen(pszSTR2));
pszResult = (char*)malloc(nlen);
strcpy(pszResult, pszSTR1);
strcat(pszResult, pszSTR2);
jstring jstrRe = stoJstring(env, pszResult);
free(pszSTR1);
free(pszSTR2);
free(pszResult);
return(jstrRe);
}