Expand description
§Class File Format
Reader and writer for the Java class file format, supporting the parsing and generation of standard JVM class file structures.
§Overview
The Class file format is the standard binary format executed by the Java Virtual Machine. This module provides:
- Class File Reading: Parsing class file structures from binary data.
- Class File Writing: Serializing class file structures into binary data.
- Full Support: Supports all standard class file components.
- Validation Mechanism: Built-in format validation and error checking.
- Performance Optimization: Efficient handling of large class files.
§Class File Structure
Java class files follow a strict binary format.
§Supported Versions
| Java Version | Major Version | Minor Version | Support Status |
|---|---|---|---|
| Java 1.1 | 45 | 3 | ✅ Supported |
| Java 1.2 | 46 | 0 | ✅ Supported |
| Java 1.3 | 47 | 0 | ✅ Supported |
| Java 1.4 | 48 | 0 | ✅ Supported |
| Java 5 | 49 | 0 | ✅ Supported |
| Java 6 | 50 | 0 | ✅ Supported |
| Java 7 | 51 | 0 | ✅ Supported |
| Java 8 | 52 | 0 | ✅ Supported |
| Java 9 | 53 | 0 | ✅ Supported |
| Java 10 | 54 | 0 | ✅ Supported |
| Java 11 | 55 | 0 | ✅ Supported |
| Java 12 | 56 | 0 | ✅ Supported |
| Java 13 | 57 | 0 | ✅ Supported |
| Java 14 | 58 | 0 | ✅ Supported |
| Java 15 | 59 | 0 | ✅ Supported |
| Java 16 | 60 | 0 | ✅ Supported |
| Java 17 | 61 | 0 | ✅ Supported |
| Java 18 | 62 | 0 | ✅ Supported |
| Java 19 | 63 | 0 | ✅ Supported |
| Java 20 | 64 | 0 | ✅ Supported |
| Java 21 | 65 | 0 | ✅ Supported |
§Constant Pool Types
Supports all standard constant pool entry types:
§Basic Types
- CONSTANT_Utf8: UTF-8 encoded string
- CONSTANT_Integer: 32-bit integer
- CONSTANT_Float: 32-bit floating point
- CONSTANT_Long: 64-bit long integer
- CONSTANT_Double: 64-bit double precision floating point
§Reference Types
- CONSTANT_Class: Symbolic reference to a class or interface
- CONSTANT_String: Symbolic reference to a string object
- CONSTANT_Fieldref: Symbolic reference to a field
- CONSTANT_Methodref: Symbolic reference to a class method
- CONSTANT_InterfaceMethodref: Symbolic reference to an interface method
- CONSTANT_NameAndType: Name and type descriptor for a field or method
§Dynamic Types
- CONSTANT_MethodHandle: Method handle
- CONSTANT_MethodType: Method type
- CONSTANT_Dynamic: Dynamically-computed constant
- CONSTANT_InvokeDynamic: Dynamic method invocation
§Attribute Support
§Standard Attributes
- Code: Bytecode and exception table of a method
- ConstantValue: Constant value of a constant field
- SourceFile: Source file name
- LineNumberTable: Mapping from bytecode to source code line numbers
- LocalVariableTable: Debug information for local variables
- LocalVariableTypeTable: Debug information for generic local variables
§Advanced Attributes
- StackMapTable: Stack map frames (used for verification)
- Exceptions: Exception types thrown by a method
- InnerClasses: Inner class information
- EnclosingMethod: Enclosing method for anonymous classes
- Signature: Generic signature information
- RuntimeVisibleAnnotations: Annotations visible at runtime
- RuntimeInvisibleAnnotations: Annotations invisible at runtime
§Usage Examples
§Reading a Class File
(Examples to be added)
§Writing a Class File
(Examples to be added)
§Error Handling
Potential errors during class file reading and writing:
§Reading Errors
- Magic Number Error: Invalid class file magic number.
- Version Not Supported: Unsupported Java version.
- Format Error: Corrupted class file format.
- Constant Pool Error: Invalid constant pool reference.
- Validation Error: Bytecode verification failed.
§Writing Errors
- Data Too Large: Exceeds class file format limits.
- Reference Error: Invalid cross-reference.
- Encoding Error: String encoding issues.
All errors are returned via the GaiaError type, providing detailed error information.
§Performance Characteristics
- Memory Efficiency: Streaming processing for large class files.
- Fast Parsing: Optimized binary parsing algorithms.
- Zero-Copy: Minimizes memory allocation wherever possible.
- Cache-Friendly: Optimized data structure design.
§Related Modules
Modules§
Structs§
- Class
Read Config - Class 文件读取配置