今天做了一个有关ContentProvider的短信备份的小案例,遇到短信备份失败,费了一番周折后终于找到了问题所在
该案例是将短信写到一个xml文件然后保存在手机存储中实现短信的备份功能,关键实现代码如下
public class SmsUtils {
public static void backUpSms(List<SmsInfo> smsInfos, Context context) {
try {
XmlSerializer serializer = Xml.newSerializer();
File file = new File(Environment.getExternalStorageDirectory(), "sms.xml");
//初始化序列化器,指定xml数据写入到哪个文件,并且指定文件的编码方式
FileOutputStream os = new FileOutputStream(file);
serializer.setOutput(os, "utf-8");
serializer.startDocument("utf-8", true);
//构建根节点
serializer.startTag(null, "smss");
for (SmsInfo info : smsInfos) {
//构建父节点开始号标签
serializer.startTag(null, "sms");
serializer.attribute(null, "id", info.getId() + "");
//构建子节点body
serializer.startTag(null, "body");
serializer.text(info.getBody());
serializer.endTag(null, "body");
//构建子节点address
serializer.startTag(null, "address");
serializer.text(info.getAddress());
serializer.endTag(null, "address");
//构建子节点type
serializer.startTag(null, "type");
serializer.text(info.getType() + "");
serializer.endTag(null, "type");
//构建子节点date
serializer.startTag(null, "date");
serializer.text(info.getDate() + "");
serializer.endTag(null, "date");
//父节点结束标签
serializer.endTag(null, "sms");
}
serializer.endTag(null, "smss");
serializer.endDocument();
os.close();
Toast.makeText(context, "备份成功", Toast.LENGTH_LONG).show();
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(context, "备份失败", Toast.LENGTH_LONG).show();
}
}
}
下面是Logcat打印的信息
07-13 16:44:18.195 26990-26990/wp.contentresolver D/StubController: holdAndGetPermissionType permissionType:4 uid:10382 pid:26990
07-13 16:44:18.195 26990-26990/wp.contentresolver D/StubController: addRequestCount, mRequestCount =1 mPhoneIDRequestCount: 0 mLocationRequestCount: 0 permissionType is: 4
07-13 16:44:18.195 26990-26990/wp.contentresolver D/StubController: holdForGetPermissionSelection mRequestCount:1
07-13 16:44:18.200 26990-26990/wp.contentresolver D/StubController: beforeShowDialogCheckResult:1
07-13 16:44:18.200 26990-26990/wp.contentresolver D/StubController: minusRequestCount, mRequestCount =0 mPhoneIDRequestCount: 0 mLocationRequestCount: 0 permissionType is: 4
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: java.lang.IllegalArgumentException: Illegal character (d83d)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at org.kxml2.io.KXmlSerializer.reportInvalidCharacter(KXmlSerializer.java:144)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at org.kxml2.io.KXmlSerializer.writeEscaped(KXmlSerializer.java:130)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at org.kxml2.io.KXmlSerializer.text(KXmlSerializer.java:536)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at wp.contentresolver.SmsUtils.backUpSms(SmsUtils.java:56)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at wp.contentresolver.MainActivity.click(MainActivity.java:36)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at java.lang.reflect.Method.invokeNative(Native Method)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at java.lang.reflect.Method.invoke(Method.java:515)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at android.view.View.performClick(View.java:4446)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at android.view.View$PerformClick.run(View.java:18480)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at android.os.Handler.handleCallback(Handler.java:733)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at android.os.Handler.dispatchMessage(Handler.java:95)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at android.os.Looper.loop(Looper.java:136)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at android.app.ActivityThread.main(ActivityThread.java:5315)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at java.lang.reflect.Method.invokeNative(Native Method)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at java.lang.reflect.Method.invoke(Method.java:515)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:864)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:680)
07-13 16:44:18.220 26990-26990/wp.contentresolver W/System.err: at dalvik.system.NativeStart.main(Native Method)
由于Logcat上没有明显的错误信息,盲目的在真机上测试了多遍,都是以失败告终,代码检查了多遍也都没有问题,于是感觉是手机系统的问题,毕竟前面有过这样的情况,
就拿同学的手机测试了一下,结果显示备份成功了,猜想是正确的吗? --当然不是,看着Logcat上的错误信息,继续了探究,询问了导员后,开始了错误的排查,问题最终就是定位在将短信写入xml上,
首先将增强for循环去掉,只写了一个简单的头尾节点,结果成功了,又依次增加了几个子节点,将text写成固定的内容,运行起来备份又成功了,因此,可以知道自己的真机可以正常的写xml文件
又将节点中text属性固定的内容改成了动态的读取短信的内容(serializer.text(smsInfos.get(0).getBody());),这样真机也可以正常的读取短信内容并可以将其写入xml中,
最后就是for循环的问题,因为写单独的节点可以正常读取,而读取全部信息就失败,所以可以说明是其中某个信息有问题,仔细查看了一下真机上的信息,发现里面有表情,于是将所有带表情的信息都删除了,
又重新运行了一下备份,结果成功了,问题终于被解决了,不是手机系统的问题,原来是编码的转换问题,短信中的那种表情(自带的除外)不能正常的转换utf-8格式字符,导致备份失败,后来又结合了错误日志,
上面报了一个java.lang.IllegalArgumentException: Illegal character (d83d)的信息,意思是非法参数异常,下面还在body节点处报了一个错误,所以可以得出,是信息内容的问题
所以,以后一定要仔细查看Logcat错误信息并逐一排查错误,不被表面现象迷惑