android NDK开发之 c++ struct 转 java Object对象返回给java 层
Android 开发之 JNI 开发， c++ struct 转 java Object对象返回给java 层
JNI开发经常遇到 java类型和c++类型进行转换传输的事情,所以写个文章作为备份
Java 对象
package com.mgsc.sdk.model;
import java.util.List;
public class NetModel {
private String name;
private String enName;
此能力是否被调用
private boolean isCalled;
private List<Model> models;
public NetModel(){
}
public NetModel(String name, String enName, List<Model> models) {
this.name = name;
this.enName = enName;
this.models = models;
}
public boolean isCalled() {
return isCalled;
}
public void setCalled(boolean called) {
isCalled = called;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEnName() {
return enName;
}
public void setEnName(String enName) {
this.enName = enName;
}
public List<Model> getModels() {
return models;
}
public void setModels(List<Model> models) {
this.models = models;
}
public static class Model {
private String type;
private String netType;
private String fileName;
private String fileSuffix;
public Model(){
}
public Model(String type, String netType, String fileName, String fileSuffix) {
this.type = type;
this.netType = netType;
this.fileName = fileName;
this.fileSuffix = fileSuffix;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getNetType() {
return netType;
}
public void setNetType(String netType) {
this.netType = netType;
}
public String getFileName() {
return fileName;
}
public void setFileName(String fileName) {
this.fileName = fileName;
}
public String getFileSuffix() {
return fileSuffix;
}
public void setFileSuffix(String fileSuffix) {
this.fileSuffix = fileSuffix;
}
}
}
c++结构器
#include<string>
#include <vector>
namespace MGSC {
struct AIModel {
std::string type;
std::string netType;
std::string fileName;
std::string fileSuffix;
};
struct AIAbilityModel {
std::string name;
std::string enName;
std::vector<AIModel > models;
};
}
对应 JNI 的cpp 文件函数代码
MGSC::AIAbilityManager *manager = new MGSC::AIAbilityManager();
std::string cpp_str = MGSC::Util::GetInstance()->jstring2str(env,model_config_jsonstr);
std::vector<MGSC::AIAbilityModel> aiAbilityModelvec = manager->decoderModeConfigJSON(cpp_str);
//获取ArrayList类引用
jclass listClass = env->FindClass("java/util/ArrayList");
if(listClass == NULL){
LOGE("mgsc测试:获取 listClass 类失败 ");
}
//创建ArrayList 构造函数，函数名为<init> 返回类型必须为 void 即 V
jmethodID listInitFunID = env->GetMethodID(listClass,"<init>","()V");
//创建一个ArrayList对象
jobject netModelListBean = env->NewObject(listClass,listInitFunID);
//获取ArrayList对象的add() 的 methodID
jmethodID netModelListBeanAddMethod = env->GetMethodID(listClass,"add","(Ljava/lang/Object;)Z");
for(int i=0;i<aiAbilityModelvec.size();i++){
MGSC::AIAbilityModel aiAbilityModel = aiAbilityModelvec[i];
LOGE("mgsc测试：aiAbilityModel.name %s",aiAbilityModel.name.c_str());
jclass netModelClass = env->FindClass(NetModelClassPath);
if(netModelClass == NULL){
LOGE("mgsc测试:获取 netModelClass 类失败 ");
}
//1.获取构造函数
jmethodID netModelInitFunID = env->GetMethodID(netModelClass,"<init>","()V");
//2.用构造函数创造一个对象
jobject netModelBean = env->NewObject(netModelClass,netModelInitFunID);
//3.构造想要赋值的字段
jfieldID netModeNameField = env->GetFieldID(netModelClass, "name", "Ljava/lang/String;");
jfieldID netModelEnNameField = env->GetFieldID(netModelClass,"enName","Ljava/lang/String;");
jfieldID netModelModelsField = env->GetFieldID(netModelClass,"models", "Ljava/util/List;");
jclass modelClass = env->FindClass(ModelClassPath);
if(modelClass == NULL){
LOGE("mgsc测试:获取 modelClass 类失败 ");
}
//获取ArrayList类引用
jclass listClass = env->FindClass("java/util/ArrayList");
if(listClass == NULL){
LOGE("mgsc测试:获取 listClass 类失败 ");
}
//创建ArrayList 构造函数，函数名为<init> 返回类型必须为 void 即 V
jmethodID listInitFunID = env->GetMethodID(listClass,"<init>","()V");
//创建一个ArrayList对象
jobject listBean = env->NewObject(listClass,listInitFunID);
//获取ArrayList对象的add() 的 methodID
jmethodID addMethod = env->GetMethodID(listClass,"add","(Ljava/lang/Object;)Z");
for(int j=0 ;j< aiAbilityModel.models.size();j++){
MGSC::AIModel aiModel = aiAbilityModel.models[j];
//获取构造方法
jmethodID modelInitFunID = env->GetMethodID(modelClass,"<init>","()V");
//构造对象
jobject modelBean = env->NewObject(modelClass,modelInitFunID);
//构造需要赋值的字段
jfieldID typeField = env->GetFieldID(modelClass,"type", "Ljava/lang/String;");
jfieldID netTypeField = env->GetFieldID(modelClass,"netType", "Ljava/lang/String;");
jfieldID fileNameField = env->GetFieldID(modelClass,"fileName", "Ljava/lang/String;");
jfieldID fileSuffixField = env->GetFieldID(modelClass,"fileSuffix", "Ljava/lang/String;");
//给对应的字段赋值（要赋值的对象，要赋值的字段，要赋值的值，jni类型的）
env->SetObjectField(modelBean,typeField,env->NewStringUTF(aiModel.type.c_str()));
env->SetObjectField(modelBean,netTypeField,env->NewStringUTF(aiModel.netType.c_str()));
env->SetObjectField(modelBean,fileNameField,env->NewStringUTF(aiModel.fileName.c_str()));
env->SetObjectField(modelBean,fileSuffixField,env->NewStringUTF(aiModel.fileSuffix.c_str()));
env->CallBooleanMethod(listBean,addMethod,modelBean);
}
//给对应的字段赋值
env->SetObjectField(netModelBean,netModeNameField,env->NewStringUTF(aiAbilityModel.name.c_str()));
env->SetObjectField(netModelBean,netModelEnNameField,env->NewStringUTF(aiAbilityModel.enName.c_str()));
env->SetObjectField(netModelBean,netModelModelsField,listBean);
env->CallBooleanMethod(netModelListBean,netModelListBeanAddMethod,netModelBean);
}
manager->Release();
return netModelListBean;
最后返回对应java的类型为： List
