| java.lang.Object
 org.objectweb.asm.ClassReader
| ClassReader | | public class ClassReader (Code) | | A Java class parser to make a
ClassVisitor visit an existing class.
This class parses a byte array conforming to the Java class file format and
calls the appropriate visit methods of a given class visitor for each field,
method and bytecode instruction encountered.
author:
Eric Bruneton
author:
Eugene Kuleshov |
| Field Summary | |
| final static boolean | ANNOTATIONS
True to enable annotations support. | | final public static int | EXPAND_FRAMES
Flag to expand the stack map frames. | | final static boolean | FRAMES
True to enable stack map frames support. | | final static boolean | RESIZE
True to enable JSR_W and GOTO_W support. | | final static boolean | SIGNATURES
True to enable signatures support. | | final public static int | SKIP_CODE
Flag to skip method code. | | final public static int | SKIP_DEBUG
Flag to skip the debug information in the class. | | final public static int | SKIP_FRAMES
Flag to skip the stack map frames in the class. | | final static boolean | WRITER
True to enable bytecode writing support. | | final public byte[] | b
The class to be parsed. | | final public int | header
Start index of the class header information (access, name...) in
ClassReader.b b . |
| ANNOTATIONS | | final static boolean ANNOTATIONS(Code) | | True to enable annotations support.
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| EXPAND_FRAMES | | final public static int EXPAND_FRAMES(Code) | | Flag to expand the stack map frames. By default stack map frames are
visited in their original format (i.e. "expanded" for classes whose
version is less than V1_6, and "compressed" for the other classes). If
this flag is set, stack map frames are always visited in expanded format
(this option adds a decompression/recompression step in ClassReader and
ClassWriter which degrades performances quite a lot).
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| FRAMES | | final static boolean FRAMES(Code) | | True to enable stack map frames support.
|
| RESIZE | | final static boolean RESIZE(Code) | | True to enable JSR_W and GOTO_W support.
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| SIGNATURES | | final static boolean SIGNATURES(Code) | | True to enable signatures support.
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| SKIP_CODE | | final public static int SKIP_CODE(Code) | | Flag to skip method code. If this class is set CODE
attribute won't be visited. This can be used, for example, to retrieve
annotations for methods and method parameters.
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| SKIP_FRAMES | | final public static int SKIP_FRAMES(Code) | | Flag to skip the stack map frames in the class. If this flag is set the
stack map frames of the class is not visited, i.e. the
MethodVisitor.visitFrame visitFrame method will not be called.
This flag is useful when the
ClassWriter.COMPUTE_FRAMES option is
used: it avoids visiting frames that will be ignored and recomputed from
scratch in the class writer.
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| WRITER | | final static boolean WRITER(Code) | | True to enable bytecode writing support.
|
| b | | final public byte[] b(Code) | | The class to be parsed. The content of this array must not be
modified. This field is intended for
Attribute sub classes, and
is normally not needed by class generators or adapters.
|
| header | | final public int header(Code) | | Start index of the class header information (access, name...) in
ClassReader.b b .
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| ClassReader | | public ClassReader(byte[] b)(Code) | | Constructs a new
ClassReader object.
Parameters:
b - the bytecode of the class to be read. |
| ClassReader | | public ClassReader(byte[] b, int off, int len)(Code) | | Constructs a new
ClassReader object.
Parameters:
b - the bytecode of the class to be read.
Parameters:
off - the start offset of the class data.
Parameters:
len - the length of the class data. |
| ClassReader | | public ClassReader(String name) throws IOException(Code) | | Constructs a new
ClassReader object.
Parameters:
name - the fully qualified name of the class to be read.
throws:
IOException - if an exception occurs during reading. |
| accept | | public void accept(ClassVisitor classVisitor, Attribute[] attrs, int flags)(Code) | | Makes the given visitor visit the Java class of this
ClassReader .
This class is the one specified in the constructor (see
ClassReader.ClassReader(byte[]) ClassReader ).
Parameters:
classVisitor - the visitor that must visit this class.
Parameters:
attrs - prototypes of the attributes that must be parsed during thevisit of the class. Any attribute whose type is not equal to thetype of one the prototypes will not be parsed: its byte arrayvalue will be passed unchanged to the ClassWriter. This maycorrupt it if this value contains references to the constant pool,or has syntactic or semantic links with a class element that hasbeen transformed by a class adapter between the reader and thewriter.
Parameters:
flags - option flags that can be used to modify the default behaviorof this class. See ClassReader.SKIP_DEBUG, ClassReader.EXPAND_FRAMES,ClassReader.SKIP_FRAMES, ClassReader.SKIP_CODE. |
| getItem | | public int getItem(int item)(Code) | | Returns the start index of the constant pool item in
ClassReader.b b , plus
one. This method is intended for
Attribute sub classes, and is
normally not needed by class generators or adapters.
Parameters:
item - the index a constant pool item. the start index of the constant pool item in ClassReader.b b, plusone. |
| readByte | | public int readByte(int index)(Code) | | Reads a byte value in
ClassReader.b b . This method is intended for
Attribute sub classes, and is normally not needed by class
generators or adapters.
Parameters:
index - the start index of the value to be read in ClassReader.b b. the read value. |
| readClass | | public String readClass(int index, char[] buf)(Code) | | Reads a class constant pool item in
ClassReader.b b . This method is
intended for
Attribute sub classes, and is normally not needed by
class generators or adapters.
Parameters:
index - the start index of an unsigned short value in ClassReader.b b,whose value is the index of a class constant pool item.
Parameters:
buf - buffer to be used to read the item. This buffer must besufficiently large. It is not automatically resized. the String corresponding to the specified class item. |
| readConst | | public Object readConst(int item, char[] buf)(Code) | | Reads a numeric or string constant pool item in
ClassReader.b b . This
method is intended for
Attribute sub classes, and is normally not
needed by class generators or adapters.
Parameters:
item - the index of a constant pool item.
Parameters:
buf - buffer to be used to read the item. This buffer must besufficiently large. It is not automatically resized. the Integer, Float, Long,Double, String or Type corresponding tothe given constant pool item. |
| readInt | | public int readInt(int index)(Code) | | Reads a signed int value in
ClassReader.b b . This method is intended for
Attribute sub classes, and is normally not needed by class
generators or adapters.
Parameters:
index - the start index of the value to be read in ClassReader.b b. the read value. |
| readLabel | | protected Label readLabel(int offset, Label[] labels)(Code) | | Returns the label corresponding to the given offset. The default
implementation of this method creates a label for the given offset if it
has not been already created.
Parameters:
offset - a bytecode offset in a method.
Parameters:
labels - the already created labels, indexed by their offset. If alabel already exists for offset this method must not create a newone. Otherwise it must store the new label in this array. a non null Label, which must be equal to labels[offset]. |
| readLong | | public long readLong(int index)(Code) | | Reads a signed long value in
ClassReader.b b . This method is intended
for
Attribute sub classes, and is normally not needed by class
generators or adapters.
Parameters:
index - the start index of the value to be read in ClassReader.b b. the read value. |
| readShort | | public short readShort(int index)(Code) | | Reads a signed short value in
ClassReader.b b . This method is intended
for
Attribute sub classes, and is normally not needed by class
generators or adapters.
Parameters:
index - the start index of the value to be read in ClassReader.b b. the read value. |
| readUTF8 | | public String readUTF8(int index, char[] buf)(Code) | | Reads an UTF8 string constant pool item in
ClassReader.b b . This method
is intended for
Attribute sub classes, and is normally not needed
by class generators or adapters.
Parameters:
index - the start index of an unsigned short value in ClassReader.b b,whose value is the index of an UTF8 constant pool item.
Parameters:
buf - buffer to be used to read the item. This buffer must besufficiently large. It is not automatically resized. the String corresponding to the specified UTF8 item. |
| readUnsignedShort | | public int readUnsignedShort(int index)(Code) | | Reads an unsigned short value in
ClassReader.b b . This method is
intended for
Attribute sub classes, and is normally not needed by
class generators or adapters.
Parameters:
index - the start index of the value to be read in ClassReader.b b. the read value. |
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