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AttributeFactory.javaAPI DocAndroid 1.5 API4956Wed May 06 22:41:02 BST 2009com.android.dx.cf.direct

AttributeFactory

public class AttributeFactory extends Object
Factory capable of instantiating various {@link Attribute} subclasses depending on the context and name.

Fields Summary
public static final int
CTX_CLASS
context for attributes on class files
public static final int
CTX_FIELD
context for attributes on fields
public static final int
CTX_METHOD
context for attributes on methods
public static final int
CTX_CODE
context for attributes on code attributes
public static final int
CTX_COUNT
number of contexts
Constructors Summary
public AttributeFactory()
Constructs an instance.


            
      
        // This space intentionally left blank.
Methods Summary
public final com.android.dx.cf.iface.Attributeparse(DirectClassFile cf, int context, int offset, com.android.dx.cf.iface.ParseObserver observer)
Parses and makes an attribute based on the bytes at the indicated position in the given array. This method figures out the name, and then does all the setup to call on to {@link #parse0}, which does the actual construction.

param
cf non-null; class file to parse from
param
context context to parse in; one of the CTX_* constants
param
offset offset into dcf's bytes to start parsing at
param
observer null-ok; parse observer to report to, if any
return
non-null; an appropriately-constructed {@link Attribute}

        if (cf == null) {
            throw new NullPointerException("cf == null");
        }

        if ((context < 0) || (context >= CTX_COUNT)) {
            throw new IllegalArgumentException("bad context");
        }

        CstUtf8 name = null;

        try {
            ByteArray bytes = cf.getBytes();
            ConstantPool pool = cf.getConstantPool();
            int nameIdx = bytes.getUnsignedShort(offset);
            int length = bytes.getInt(offset + 2);

            name = (CstUtf8) pool.get(nameIdx);

            if (observer != null) {
                observer.parsed(bytes, offset, 2,
                                "name: " + name.toHuman());
                observer.parsed(bytes, offset + 2, 4,
                                "length: " + Hex.u4(length));
            }

            return parse0(cf, context, name.getString(), offset + 6, length,
                          observer);
        } catch (ParseException ex) {
            ex.addContext("...while parsing " + 
                    ((name != null) ? (name.toHuman() + " ") : "") +
                    "attribute at offset " + Hex.u4(offset));
            throw ex;
        }
protected com.android.dx.cf.iface.Attributeparse0(DirectClassFile cf, int context, java.lang.String name, int offset, int length, com.android.dx.cf.iface.ParseObserver observer)
Parses attribute content. The base class implements this by constructing an instance of {@link RawAttribute}. Subclasses are expected to override this to do something better in most cases.

param
cf non-null; class file to parse from
param
context context to parse in; one of the CTX_* constants
param
name non-null; the attribute name
param
offset offset into bytes to start parsing at; this is the offset to the start of attribute data, not to the header
param
length the length of the attribute data
param
observer null-ok; parse observer to report to, if any
return
non-null; an appropriately-constructed {@link Attribute}

        ByteArray bytes = cf.getBytes();
        ConstantPool pool = cf.getConstantPool();
        Attribute result = new RawAttribute(name, bytes, offset, length, pool);

        if (observer != null) {
            observer.parsed(bytes, offset, length, "attribute data");
        }

        return result;