Android 6.0 (Marshmallow) static initialization exception on getDeclaredField() in svg-android library

Question

I'm having some serious problem with this code, from svg-android:

public class ParserHelper {

private static final Field STRING_CHARS;
static {
    try {
        STRING_CHARS = String.class.getDeclaredField("value"); //<-- exception here
        STRING_CHARS.setAccessible(true);
    } catch (Exception e) {
        throw new RuntimeException(e);
    }
}

private final char[] s;
private final int n;
private char current;
public int pos;

public ParserHelper(String str, int pos) {
    try {
        this.s = (char[]) STRING_CHARS.get(str); 
    } catch (Exception e) {
        throw new RuntimeException(e);
    }
    this.pos = pos;
    n = s.length;
    current = s[pos];
}

the STRING_CHARS = String.class.getDeclaredField("value");throws the excpetion

10-09 10:25:58.240: E/AndroidRuntime(3430): Caused by: java.lang.RuntimeException: java.lang.NoSuchFieldException: No field value in class Ljava/lang/String; (declaration of 'java.lang.String' appears in /system/framework/core-libart.jar)

I can't continue the job. Only in Android 6.0 Marshmallow. Any idea?

SOLVED: Now, I did not solved the static initialization issue but I changed the char[] s initialization:

public class ParserHelper {

//  private static final Field STRING_CHARS;
//  static {
//      try {
//          STRING_CHARS = String.class.getDeclaredField("value");
//          STRING_CHARS.setAccessible(true);
//      } catch (Exception e) {
//          throw new RuntimeException(e);
//      }
//  }

    private final char[] s;
    private final int n;
    private char current;
    public int pos;

    public ParserHelper(String str, int pos) {
        try {
            s = new char[str.length()];
            str.getChars(0, str.length(), this.s, 0); //<-- here
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        this.pos = pos;
        n = s.length;
        current = s[pos];
    }

Dont you need to use a String instance to perform reflection? not an expert on it. — Nanoc, Oct 09 '15 at 10:40
Then try this instead and tell me "new String("Hello").class.getDeclaredField("value");" — Nanoc, Oct 09 '15 at 10:44
@Nanoc Can't compile, error on .class "Syntax error on token class..." — Seraphim's, Oct 09 '15 at 10:52
OK silly mistake, use getClass() instead of .class "new String("Hello").getClass().getDeclaredField("value");" — Nanoc, Oct 09 '15 at 10:57
Accessing private fields via reflection is risky. They are private for a reason. — Henry, Oct 09 '15 at 11:16

aga · Accepted Answer · 2015-11-26T13:35:42.580

15

Looks like the String's private field called value which holds the array of chars was renamed to ASCII in the Marshmallow. Thus you have a RuntimeException in these lines (taken from the com.larvalabs.svgandroid.ParserHelper class):

    try {
        STRING_CHARS = String.class.getDeclaredField("value");
        STRING_CHARS.setAccessible(true);
    } catch (Exception e) {
        throw new RuntimeException(e);
    }

The svgandroid is discontinued, so there is little chance that the project's author will fix this issue and push the new jar to maven.You can make your own fork of svgandroid library, merge this pull-request, build the jar and use it from now on instead of mavenized version.

Or you can go a little further, and push the fixed version to mvnrepository yourself. :)

edited Nov 26 '15 at 13:35

answered Oct 13 '15 at 11:26

aga

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Oh dear... If anyone would make a fix for this library, it would be awesome. I think many people use it, and now all of their apps are crashing on marshmallow. – Deinlandel Nov 26 '15 at 13:15
Although your answer do fix it, I wonder if it will have any impact on performance. I think it was done that way to be more efficient as the new methods create a copy and through reflection he is accessing it directly. – Gabriel Falcone May 20 '16 at 14:56

Android 6.0 (Marshmallow) static initialization exception on getDeclaredField() in svg-android library

1 Answers1