我目前正在使用某个应用程序并尝试使其与较低的api版本兼容。我已设法使其与 Android Api Level 21 Android Api Level 18 兼容。
我目前仍然坚持 17 。修复了android api 18中引入的所有新方法后，程序编译但不运行。
发生了什么
应用程序（启动程序）在开始启动时发出关于缺少JNI函数的通知。该应用程序在api级别18上编译并正常工作，但它在api级别17上不起作用，尽管它编译。</ p>
应用程序在android api级别17失败并且 peer 变量未被分配，根据android监视器，函数 create 未实现。一旦调用该应用程序，应用程序就会失败。
奇怪的是，在api 18级它运行正常。但函数create永远不会被调用，虽然它是唯一改变变量值的函数，但变量确实会改变值。
我搜索过的内容
搜索并查看 Icu库的文档。它出现在 AlphabeticIndex 类中，根本没有创建函数。
在谷歌搜索创建方法和 AlphabeticIndex ，很多启动器和应用程序正在使用与我现在相同的文件。因此，拥有这些缺少jni函数并非巧合。
在整个应用程序中放置断点，并在Api Level 17上看到，在构造函数上调用该函数。它一旦进入创建方法就会失败，并且变量 peer 不会更改。
在android api level 18上，类构造函数被调用但它没有运行。没有来自 Log.e 语句的消息即将出现，而在重新布局时，它会跳过构造函数和函数，只是更改变量 peer 值。
更改变量的函数只有一个用法，就是您在此处看到的用法。
对变量 peer 进行观看，我发现价值会发生变化，但我显然不明白为什么。任何想法或建议？你们之前有过ICU图书馆经验的人吗？
代码
/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package libcore.icu;
import android.util.Log;
import java.util.Locale;
/**
* Exposes icu4c's AlphabeticIndex.
*/
public final class AlphabeticIndex {
// Breakpoint here
/**
* Exposes icu4c's ImmutableIndex (new to icu 51). This exposes a read-only,
* thread safe snapshot view of an AlphabeticIndex at the moment it was
* created, and allows for random access to buckets by index.
*/
public static final class ImmutableIndex {
private long peer;
private ImmutableIndex(long peer) {
this.peer = peer;
}
@Override protected synchronized void finalize() throws Throwable {
try {
destroy(peer);
peer = 0;
} finally {
super.finalize();
}
}
/**
* Returns the number of the label buckets in this index.
*/
public int getBucketCount() {
return getBucketCount(peer);
}
/**
* Returns the index of the bucket in which 's' should appear.
* Function is synchronized because underlying routine walks an iterator
* whose state is maintained inside the index object.
*/
public int getBucketIndex(String s) {
return getBucketIndex(peer, s);
}
/**
* Returns the label for the bucket at the given index (as returned by getBucketIndex).
*/
public String getBucketLabel(int index) {
return getBucketLabel(peer, index);
}
private static native int getBucketCount(long peer);
private static native int getBucketIndex(long peer, String s);
private static native String getBucketLabel(long peer, int index);
}
// watch here
private long peer;
/**
* Creates a new AlphabeticIndex for the given locale.
*/
public AlphabeticIndex(Locale locale) {
Log.e("Debbugingthisone", "Method called");
try {
// breakpoint here
peer = create(locale.toString());
}
catch(Exception e){
Log.e("Debuggingthisone", "Problem" + e.toString());
}
Log.e("Debuggingthisone", "Constructor call finished");
}
@Override protected synchronized void finalize() throws Throwable {
try {
destroy(peer);
peer = 0;
} finally {
super.finalize();
}
}
/**
* Returns the max number of the label buckets allowed in this index.
*/
public synchronized int getMaxLabelCount() {
return getMaxLabelCount(peer);
}
/**
* Sets the max number of the label buckets in this index.
* (ICU 51 default is 99)
*/
public synchronized AlphabeticIndex setMaxLabelCount(int count) {
setMaxLabelCount(peer, count);
Log.e("Arlind","peer vlera " + peer);
return this;
}
/**
* Adds the index characters from the given locale to the index.
* The labels are added to those that are already in the index;
* they do not replace the existing index characters.
* The collation order for this index is not changed;
* it remains that of the locale that was originally specified
* when creating this index.
*/
public synchronized AlphabeticIndex addLabels(Locale locale) {
addLabels(peer, locale.toString());
return this;
}
/**
* Adds the index characters in the range between the specified start and
* end code points, inclusive.
*/
public synchronized AlphabeticIndex addLabelRange(int codePointStart, int codePointEnd) {
addLabelRange(peer, codePointStart, codePointEnd);
return this;
}
/**
* Returns the number of the label buckets in this index.
*/
public synchronized int getBucketCount() {
return getBucketCount(peer);
}
/**
* Returns the index of the bucket in which 's' should appear.
* Function is synchronized because underlying routine walks an iterator
* whose state is maintained inside the index object.
*/
public synchronized int getBucketIndex(String s) {
return getBucketIndex(peer, s);
}
/**
* Returns the label for the bucket at the given index (as returned by getBucketIndex).
*/
public synchronized String getBucketLabel(int index) {
return getBucketLabel(peer, index);
}
/**
* Returns an ImmutableIndex created from this AlphabeticIndex.
*/
public synchronized ImmutableIndex getImmutableIndex() {
return new ImmutableIndex(buildImmutableIndex(peer));
}
private static native long create(String locale);
private static native void destroy(long peer);
private static native int getMaxLabelCount(long peer);
private static native void setMaxLabelCount(long peer, int count);
private static native void addLabels(long peer, String locale);
private static native void addLabelRange(long peer, int codePointStart, int codePointEnd);
private static native int getBucketCount(long peer);
private static native int getBucketIndex(long peer, String s);
private static native String getBucketLabel(long peer, int index);
private static native long buildImmutableIndex(long peer);
}