xapi.bytecode.ParameterAnnotationsAttribute Maven / Gradle / Ivy

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package xapi.bytecode;

import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.util.Map;

import xapi.bytecode.AnnotationsAttribute.Copier;
import xapi.bytecode.AnnotationsAttribute.Parser;


public class ParameterAnnotationsAttribute extends AttributeInfo {
    /**
     * The name of the RuntimeVisibleParameterAnnotations
     * attribute.
     */
    public static final String visibleTag
        = "RuntimeVisibleParameterAnnotations";

    /**
     * The name of the RuntimeInvisibleParameterAnnotations
     * attribute.
     */
    public static final String invisibleTag
        = "RuntimeInvisibleParameterAnnotations";
    /**
     * Constructs
     * a Runtime(In)VisibleParameterAnnotations_attribute.
     *
     * @param cp            constant pool
     * @param attrname      attribute name (visibleTag or
     *                      invisibleTag).
     * @param info          the contents of this attribute.  It does not
     *                      include attribute_name_index or
     *                      attribute_length.
     */
    public ParameterAnnotationsAttribute(ConstPool cp, String attrname,
                                         byte[] info) {
        super(cp, attrname, info);
    }

    /**
     * Constructs an empty
     * Runtime(In)VisibleParameterAnnotations_attribute.
     * A new annotation can be later added to the created attribute
     * by setAnnotations().
     *
     * @param cp            constant pool
     * @param attrname      attribute name (visibleTag or
     *                      invisibleTag).
     * @see #setAnnotations(Annotation[][])
     */
    public ParameterAnnotationsAttribute(ConstPool cp, String attrname) {
        this(cp, attrname, new byte[] { 0 });
    }

    /**
     * @param n     the attribute name.
     */
    ParameterAnnotationsAttribute(ConstPool cp, int n, DataInputStream in)
        throws IOException
    {
        super(cp, n, in);
    }

    /**
     * Returns num_parameters.
     */
    public int numParameters() {
        return info[0] & 0xff;
    }

    /**
     * Copies this attribute and returns a new copy.
     */
    @Override
    public AttributeInfo copy(ConstPool newCp, Map classnames) {
      Copier copier = new Copier(info, constPool, newCp, classnames);
        try {
            copier.parameters();
            return new ParameterAnnotationsAttribute(newCp, getName(),
                                                     copier.close());
        }
        catch (Exception e) {
            throw new RuntimeException(e.toString());
        }
    }

    /**
     * Parses the annotations and returns a data structure representing
     * that parsed annotations.  Note that changes of the node values of the
     * returned tree are not reflected on the annotations represented by
     * this object unless the tree is copied back to this object by
     * setAnnotations().
     *
     * @return Each element of the returned array represents an array of
     * annotations that are associated with each method parameter.
     *
     * @see #setAnnotations(Annotation[][])
     */
    public Annotation[][] getAnnotations() {
        try {
            return new Parser(info, constPool).parseParameters();
        }
        catch (Exception e) {
            throw new RuntimeException(e.toString());
        }
    }

    /**
     * Changes the annotations represented by this object according to
     * the given array of Annotation objects.
     *
     * @param params        the data structure representing the
     *                      new annotations. Every element of this array
     *                      is an array of Annotation and
     *                      it represens annotations of each method parameter.
     */
    public void setAnnotations(Annotation[][] params) {
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        AnnotationsWriter writer = new AnnotationsWriter(output, constPool);
        try {
            int n = params.length;
            writer.numParameters(n);
            for (int i = 0; i < n; ++i) {
                Annotation[] anno = params[i];
                writer.numAnnotations(anno.length);
                for (int j = 0; j < anno.length; ++j)
                    anno[j].write(writer);
            }

            writer.close();
        }
        catch (IOException e) {
            throw new RuntimeException(e);      // should never reach here.
        }

        set(output.toByteArray());
    }
}