changcsw的专栏

1.封装个log.h

#ifndef __MULTI_TRACE_H__#define __MULTI_TRACE_H__#ifdef ANDROID_NDK_BUILD#define LOG_TAG "NATIVE NDK INFO"#include <android/log.h> // only use in NDK#define LOGE(…) ((void)__android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__))#define LOGD(…) ((void)__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__))#define LOGI(…) ((void)__android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__))#define LOGW(…) ((void)__android_log_print(ANDROID_LOG_WARN, LOG_TAG, __VA_ARGS__))#elif defined ANDROID_SOURCE_BUILD#define LOG_TAG "NATIVE SRC INFO"extern "C" {#include <cutils/log.h> // only use in ANDROID SOURCE}#define LOGE(…) LOG(LOG_ERROR, LOG_TAG, __VA_ARGS__)#define LOGD(…) LOG(LOG_DEBUG, LOG_TAG, __VA_ARGS__)#define LOGI(…) LOG(LOG_INFO, LOG_TAG, __VA_ARGS__)#define LOGW(…) LOG(LOG_WARN, LOG_TAG, __VA_ARGS__)#elif defined IOS_PLATFORM_BUILD#define LOGE printf#define LOGD printf#define LOGI printf#define LOGW printf#elif defined WP_PLATFORM_BUILD#define LOG_TAG "NATIVE WINDOWS PHONE"#define LOG_ERROR "ERROR"#define LOG_DEBUG "DEBUG"#define LOG_INFOR "INFOR"#define LOG_WARN "WARN"void LOG(const char* status, const char* tag, const char* format, …);#define LOGE(…) LOG(LOG_ERROR, LOG_TAG, __VA_ARGS__)#define LOGD(…) LOG(LOG_DEBUG, LOG_TAG, __VA_ARGS__)#define LOGI(…) LOG(LOG_INFO, LOG_TAG, __VA_ARGS__)#define LOGW(…) LOG(LOG_WARN, LOG_TAG, __VA_ARGS__)#else#define LOGE printf#define LOGD printf#define LOGI printf#define LOGW printf#endif#endif

2.在Android.mk 中配置

LOCAL_PATH := $(call my-dir) // 设置为当前目录include $(CLEAR_VARS) // 清空变量LOCAL_MODULE := ApkPatchLibrary // 最终生成的 .so 文件 会是次名钱夹 lib (如这个名为 libxxx, 生成的.so文件包名就是此名)LOCAL_CFLAGS = -DANDROID_NDK_BUILD -D__STDC_FORMAT_MACROS -D__STDC_INT64__ // 设置这句相当于每个c/c++文件中声明了 xxxxx(-Dxxxxx)LOCAL_CXXFLAGS :=LOCAL_C_INCLUDES := $(LOCAL_PATH)LOCAL_SRC_FILES := com_lib_utils_Patch.c // 编译的c/c++文件LOCAL_LDLIBS := -lz -llog // 需要加上 这个日志才会打印出来，-l 是固定声明，（如：-lz标示加载系统 z.so包， -llog标示加载系统 log.so包）include $(BUILD_SHARED_LIBRARY) // 设置声明 动态库

3.打印日志，请看例子：

JNIEXPORT jint JNICALL Java_com_lib_utils_PatchUtils_patch(JNIEnv *env,jobject obj, jstring old, jstring new, jstring patch) {char * ch[4];ch[0] = "bspatch";ch[1] = (char*) ((*env)->GetStringUTFChars(env, old, 0));ch[2] = (char*) ((*env)->GetStringUTFChars(env, new, 0));ch[3] = (char*) ((*env)->GetStringUTFChars(env, patch, 0));LOGD("11111111111111111111");const char *str = (*env)->GetStringUTFChars(env, old, 0);const char *strnew = (*env)->GetStringUTFChars(env, new, 0);const char *strpatch = (*env)->GetStringUTFChars(env, patch, 0);LOGD("The first is %s", str);LOGD("The second is %s", strnew);LOGD("The third is %s", strpatch);LOGD("11111111111111111111");int ret = applypatch(4, ch);(*env)->ReleaseStringUTFChars(env, old, ch[1]);(*env)->ReleaseStringUTFChars(env, new, ch[2]);(*env)->ReleaseStringUTFChars(env, patch, ch[3]);return ret;}

这样就可以打印出 old, new，，patch 这三个参数（变量）的值了。

去旅行不在于记忆，而在于当时的那份心情。