[英]pathsplitting in Android with regular expressions
我在这里遵循Ajb的建议, 在Android中使用RegEx拆分字符串 ,并这样做:
@SuppressWarnings("JavaDoc")
public class DBUtility extends SQLiteOpenHelper {
private static final String DB_NAME = "Angler.sqlite3";
private static final int DB_VERSION = 1; //minimal 1, 0 nicht zulässig.
private String DB_PATH_COMPLETE;
private String DB_PATH;
private String DB_PATH_DISPLAY;
private SQLiteDatabase SQL_DB;
private Context myContext;
private String displayText;
private BufferedReader Rdr;
private char[] SQLstringAr;
private String SQLstatementFile;
private Cursor cur;
/**
* Constructor
* Takes and keeps a reference of the passed context in order to access to the application assets and resources.
* @param context
*/
public DBUtility(Context context) {
// Kann nicht private werden
super(context, DB_NAME, null, DB_VERSION); //3. Parameter Wert null ist die CursorFactory
myContext = context;
DB_PATH = myContext.getDatabasePath(DB_NAME).getPath();
String RegEx = "((/data/data/(w+\\.w+/w+/w+/))w+\\.w+)"; // /data/data/wolfgang_jakobi.anglerapp/databases/Angler.sqlite3
Pattern p = Pattern.compile(RegEx);
Matcher m = p.matcher(DB_PATH);
String [] Groups = new String[3];
if (m.find()) {
Groups[0] = m.group(1); // /data/data/wolfgang_jakobi.anglerapp/databases/Angler.sqlite3
Groups[1] = m.group(2); // /data/data/wolfgang_jakobi.anglerapp/databases/
Groups[2] = m.group(4); // wolfgang_jakobi.anglerapp/databases/
}
DB_PATH_COMPLETE = Groups[0];
DB_PATH = Groups[1];
DB_PATH_DISPLAY = Groups[2];
SQL_DB = super.getReadableDatabase();
}
the,条件m.find()变为不正确,因此代码在条件括号内并且我所有的组都为空之后继续执行,我不知道为什么。
感谢您的推荐。
沃尔夫冈
我认为您的正则表达式是错误的。
"((/data/data/(w+\\\\.w+/w+/w+/))w+\\\\.w+)"
看起来您正在尝试使用单词字符预定义字符类 ,但是按照书面说明,您只是在寻找w
字符。 也就是说,您需要在模式中使用\\\\w
而不是w
。
"((/data/data/(\\w+\\.\\w+/\\w+/\\w+/))\\w+\\.\\w+)"
我用C ++和ABAP开发了带有正则表达式的软件,可惜我在Android Studio(JAVA)中没有遵循相同的策略:已知的模式组必须先将其设置为正则表达式,然后才能逐渐替换每个组通过通配符,在本问题中,我使用通配符“ \\ w +”作为Ben的建议。
这样做后,我发现我的分组很麻烦,因为第三个“ w +”是多余的,但是我从未尝试过该错误是否有任何影响。
这是我的新代码,其中留下了用通配符替换的每一步作为注释:
@SuppressWarnings("JavaDoc")
public class DBUtility extends SQLiteOpenHelper {
private static final String DB_NAME = "Angler.sqlite3";
private static final int DB_VERSION = 1; //minimal 1, 0 nicht zulässig.
private String DB_PATH_COMPLETE;
private String DB_PATH;
private String DB_PATH_DISPLAY;
private SQLiteDatabase SQL_DB;
private Context myContext;
private String displayText;
private BufferedReader Rdr;
private char[] SQLstringAr;
private String SQLstatementFile;
private Cursor cur;
/**
* Constructor
* Takes and keeps a reference of the passed context in order to access to the application assets and resources.
* @param context
*/
public DBUtility(Context context) {
// Kann nicht private werden
super(context, DB_NAME, null, DB_VERSION); //3. Parameter Wert null ist die CursorFactory
myContext = context;
DB_PATH = myContext.getDatabasePath(DB_NAME).getPath();
//String RegEx = "((/data/data/(wolfgang_jakobi\\.anglerapp/databases/))Angler\\.sqlite3)";
// /data/data/ wolfgang_jakobi .anglerapp/databases/Angler.sqlite3
//String RegEx = "((/data/data/(\\w+\\.anglerapp/databases/))Angler\\.sqlite3)";
//String RegEx = "((/data/data/(\\w+\\.\\w+/databases/))Angler\\.sqlite3)";
//String RegEx = "((/data/data/(\\w+\\.\\w+/\\w+/))Angler\\.sqlite3)";
//String RegEx = "((/data/data/(\\w+\\.\\w+/\\w+/))\\w+\\.sqlite3)";
String RegEx = "((/data/data/(\\w+\\.\\w+ /\\w+/))\\w+\\.\\w+)";
// previous version "((/data/data/( w+\\. w+/w+/ w+/))w+\\.w+)"
Pattern p = Pattern.compile(RegEx);
Matcher m = p.matcher(DB_PATH);
String [] Groups = new String[3];
if (m.find()) {
Groups[0] = m.group(1); // /data/data/wolfgang_jakobi.anglerapp/databases/Angler.sqlite3
Groups[1] = m.group(2); // /data/data/wolfgang_jakobi.anglerapp/databases/
Groups[2] = m.group(3); // wolfgang_jakobi.anglerapp/databases/
}
DB_PATH_COMPLETE = Groups[0];
DB_PATH = Groups[1];
DB_PATH_DISPLAY = Groups[2];
SQL_DB = super.getReadableDatabase();
}
此代码可以正常工作。
沃尔夫冈的问候
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