专做丰田车货款的网站,望野古诗王绩,wordpress新闻视频站,长春网站上排名基于JNI 实现 嵌套 List 类型参数解析 背景分析解决 背景
在前面两篇文章中#xff0c;我们总结了Java 调用 C/C SDK 的几种方案#xff0c;分享了JNI在实践过程中的一些踩坑点#xff0c;而在这篇文章将继续分享针对Java List类型及其嵌套类型#xff0c;我们的JNI如何接… 基于JNI 实现 嵌套 List 类型参数解析 背景分析解决 背景
在前面两篇文章中我们总结了Java 调用 C/C SDK 的几种方案分享了JNI在实践过程中的一些踩坑点而在这篇文章将继续分享针对Java List类型及其嵌套类型我们的JNI如何接收。
分析
如下是我的的SDK的结构体定义
struct CustomParam{std::string key;std::vectorstd::string values;
};SDK的请求体入参定义如下
struct Request
{std::string ref_text;std::vectorCustomParam word_list; Request operator(const Request other){ref_text other.ref_text;word_list other.word_list;return *this;}
};解决
● 根据上面的SDK结构体的相关定义我们在Java层可以有如下的 类型定义
public class CustomParam {String key ;ListString values new ArrayList();public String getKey() {return key;}public void setWord(String key) {this.key key;}public ListString getValues() {return values;}public void setValues(ListString values) {this.values values;}
}● 关于native的方法申明如下
public class CustomParamNative {public static native int starts(ArrayListObject customParam);}
● 根据native方法生成 头部文件 javac -encoding utf8 -h . XXX.java ● 如下为生成的native方法的头部文件
/* DO NOT EDIT THIS FILE - it is machine generated */
#include jni.h
/* Header for class com_study_core_jni_CustomParamNative */#ifndef _Included_com_study_core_jni_CustomParamNative
#define _Included_com_study_core_jni_CustomParamNative
#ifdef __cplusplus
extern C {
#endif/** Class: com_study_core_jni_CustomParamNative* Method: starts* Signature: (JLjava/lang/String;Ljava/lang/String;F)I*/
JNIEXPORT jint JNICALL Java_com_study_core_jni_CustomParamNative_starts(JNIEnv *, jclass, jlong, jstring, jstring, jfloat);#ifdef __cplusplus
}
#endif
#endif
● 头部文件的具体实现
#include com_study_core_jni_CustomParamNative.h
#include vector
#undef __request
#define __request Request#include stdio.h
#include stdlib.hJNIEXPORT jint JNICALL Java_com_study_core_jni_CustomParamNative_starts(JNIEnv *env, jclass obj, jstring jni_ref, jobject customParamList)
{__request request;CopyString(env, thread-text_buff, jni_ref);request.ref_text thread-text_buff.data();CopyString(env, thread-text_buff, jni_utt);request.audio_id thread-text_buff.data();if (customParamList ! NULL){// 获取ArrayList类和对应的方法IDjclass arrayListClass env-FindClass(java/util/ArrayList);jmethodID getMethodID env-GetMethodID(arrayListClass, get, (I)Ljava/lang/Object;);jmethodID sizeMethodID env-GetMethodID(arrayListClass, size, ()I);// 获取CustomParam类和对应的字段IDjclass customParamClass env-FindClass(com/seewo/study/core/bo/CustomParam);jfieldID wordFieldID env-GetFieldID(customParamClass, key, Ljava/lang/String;);jfieldID valuesFieldID env-GetFieldID(customParamClass, values, Ljava/util/List;);// 获取ArrayList的大小jint size env-CallIntMethod(customParamList, sizeMethodID);printf(size %d\n, size);// 遍历ArrayList并解析CustomParam对象for (int i 0; i size; i){// 获取CustomParam对象jobject customParamObj env-CallObjectMethod(customParamList, getMethodID, i);// 获取key字段的值jstring wordString (jstring)env-GetObjectField(customParamObj, wordFieldID);printf(字符 %c\n, wordString);jboolean is_copy;const char *word env-GetStringUTFChars(wordString, is_copy);printf(字符 %c\n, word);// 将word和values赋值给C结构体// 创建CustomParam结构体对象CustomParam customParam;// 将word字段的值赋值给C结构体customParam.word word;// 获取values字段的值jobject valuesList env-GetObjectField(customParamObj, valuesFieldID);jclass listClass env-FindClass(java/util/List);jmethodID toArrayMethodID env-GetMethodID(listClass, toArray, ()[Ljava/lang/Object;);jobjectArray valuesArray (jobjectArray)env-CallObjectMethod(valuesList, toArrayMethodID);jsize size env-GetArrayLength(valuesArray);std::vectorstd::string values;for (int j 0; j size; j){jstring valuesString (jstring)env-GetObjectArrayElement(valuesArray, j);const char *pron env-GetStringUTFChars(valuesString, is_copy);values.push_back(pron);env-ReleaseStringUTFChars(valuesString, pron);env-DeleteLocalRef(valuesString);}customParam.values values;request.word_list.push_back(customParam);// 释放资源env-DeleteLocalRef(customParamObj);env-ReleaseStringUTFChars(wordString, word);env-DeleteLocalRef(wordString);env-DeleteLocalRef(valuesList);env-DeleteLocalRef(valuesArray);}// 释放资源env-DeleteLocalRef(arrayListClass);env-DeleteLocalRef(customParamClass);return ThreadHandleStarts__request(request);}}
