File	Doc	Category	Size	Date	Package
CodeAttribute.java	API Doc	J2ME CLDC 1.1	7306	Wed Feb 05 15:56:04 GMT 2003	kdp.classparser.attributes

CodeAttribute

• java.lang.Object
  • Attribute

Fields Summary
private int	attributeNameIndex index into constant pool table containing the name of this class
private int	attributeLength length of this attribute in bytes
private int	maxStack the maximum depth of the operand stack of this method
private int	maxLocals the number of local variables in the local variable array allocated upon invocation of this method
private int	codeLength the number of bytes in the code array for this method
private byte[]	code the bytes of Java virtual machine code that implement a method
private int	exceptionTableLength the number of entries in the exceptionTable table
private ExceptionTable[]	exceptionTable each entry describes one exception handler in the code array
private int	attributesCount the number of attributes of the Code attribute
private AttributeInfo[]	attributes array of attributes for this CodeAttribute

Constructors Summary

public CodeAttribute(DataInputStream iStream, ConstantPoolInfo[] constantPool, int attributeNameIndex, int attributeLength) Constructor. Reads the CodeAttribute attribute from the class file. param iStream the input stream on which to read the class file param constantPool constant pool of the class file param attributeNameIndex attributeNameIndex member of attribute structure. param attributeLength attributeLength member of attribute structure. exception IOException pass IOExceptions up this.attributeNameIndex = attributeNameIndex; this.attributeLength = attributeLength; //read in the maxStack and maxLocals items maxStack = iStream.readUnsignedShort (); maxLocals = iStream.readUnsignedShort (); //read in the length of the code array codeLength = iStream.readInt (); //allocate space for and read in the code array code = new byte[codeLength]; for (int lcv=0; lcv < codeLength; ++lcv) code[lcv] = iStream.readByte (); //read in the number of items in the exception table exceptionTableLength = iStream.readUnsignedShort (); //allocate space for and read in the exception table exceptionTable = new ExceptionTable[exceptionTableLength]; for (int lcv=0; lcv < exceptionTableLength; ++lcv) exceptionTable[lcv] = new ExceptionTable (iStream); //read in the number of attributes attributesCount = iStream.readUnsignedShort (); //allocate space for and read in the attributes attributes = new AttributeInfo[attributesCount]; for (int lcv=0; lcv < attributesCount; ++lcv) attributes[lcv] = new AttributeInfo (iStream, constantPool);

Methods Summary
public boolean	containsLine(int lineNumber) Query this code attribute to see if it contains the source file line number specified by lineNumber. return boolean true if the line number is in this code attribute, false otherwise //get the line number table LineNumberTableAttribute lines = getLineNumberTable (); //if the line number table was found tell it to look up the line number if (lines != null) return (lines.containsLine (lineNumber)); else return false; //could not find the line number table so return false
public int	getAttributeCount() return attributesCount;
public AttributeInfo[]	getAttributes() return attributes;
public byte[]	getByteCodes() Returns the byte code for the method return byte[] byte code byte[] ret = new byte[ code.length ]; System.arraycopy( code, 0, ret, 0, code.length ); return ret;
public int	getCodeLength() return codeLength;
public LineNumberTableAttribute	getLineNumberTable() Retrieves the line number table of this code attribute return LineNumberTableAttribute this code attribute's line number table. int attrIndex = 0; boolean found = false; //loop through this code attribute's attributes until the line number //table is found or there are no more to look through while ((!found) && (attrIndex < attributesCount)) { if (attributes[attrIndex].getType () == AttributeInfo.ATTR_LINENUMBER) found = true; else ++attrIndex; } if (found) {//if we found the line number table return it AttributeInfo attrInfo = attributes[attrIndex]; LineNumberTableAttribute lineNumberTable = (LineNumberTableAttribute) attrInfo.getInfo (); return lineNumberTable; } else return null; //did not find the line number table so return null
public java.lang.String	toString(ConstantPoolInfo[] constantPool) Returns the CodeAttribute attribute in a nice easy to read format as a string. param constantPool constant pool of the class file return String the attribute as a nice easy to read String ConstantUtf8Info utf8Info; String s = new String (""); utf8Info = (ConstantUtf8Info) constantPool[attributeNameIndex]; s = s + utf8Info.toString (); for (int lcv = 0; lcv < attributesCount; ++lcv) s = s + "\n\t\t" + attributes[lcv].toString (); return s;