package me.lzb.jvm.method;
import me.lzb.common.utils.StringUtils;
import me.lzb.jvm.attr.CodeAttr;
import me.lzb.jvm.clz.ClassFile;
import me.lzb.jvm.cmd.ByteCodeCommand;
import me.lzb.jvm.constant.UTF8Info;
import java.util.ArrayList;
import java.util.List;
/**
* Created by LZB on 2017/4/15.
*/
public class Method {
private int accessFlag;
private int nameIndex;
private int descriptorIndex;
private CodeAttr codeAttr;
private ClassFile clzFile;
public Method(ClassFile clzFile, int accessFlag, int nameIndex, int descriptorIndex) {
this.clzFile = clzFile;
this.accessFlag = accessFlag;
this.nameIndex = nameIndex;
this.descriptorIndex = descriptorIndex;
}
public int getAccessFlag() {
return accessFlag;
}
public void setAccessFlag(int accessFlag) {
this.accessFlag = accessFlag;
}
public int getNameIndex() {
return nameIndex;
}
public void setNameIndex(int nameIndex) {
this.nameIndex = nameIndex;
}
public int getDescriptorIndex() {
return descriptorIndex;
}
public void setDescriptorIndex(int descriptorIndex) {
this.descriptorIndex = descriptorIndex;
}
public CodeAttr getCodeAttr() {
return codeAttr;
}
public void setCodeAttr(CodeAttr codeAttr) {
this.codeAttr = codeAttr;
}
public ClassFile getClzFile() {
return clzFile;
}
public void setClzFile(ClassFile clzFile) {
this.clzFile = clzFile;
}
public ByteCodeCommand[] getCmds() {
return this.getCodeAttr().getCmds();
}
private String getParamAndReturnType() {
UTF8Info paramAndReturnTypeInfo = (UTF8Info) getClzFile().getConstantPool().getConstantInfo(getDescriptorIndex());
return paramAndReturnTypeInfo.getValue();
}
public List<String> getParameterList() {
//(Ljava/lang/String;I)V
String paramAndType = getParamAndReturnType();
int first = paramAndType.indexOf("(");
int last = paramAndType.lastIndexOf(")");
// Ljava/lang/String;I
String param = paramAndType.substring(first + 1, last);
List<String> paramList = new ArrayList<>();
if (StringUtils.isBlank(param)) {
return paramList;
}
while (StringUtils.isNotBlank(param)) {
int pos = 0;
// 这是一个对象类型
if (param.charAt(pos) == 'L') {
int end = param.indexOf(";");
if (end == -1) {
throw new RuntimeException("对象类型参数结尾没有\";\"");
}
paramList.add(param.substring(pos + 1, end));
pos = end + 1;
} else if (param.charAt(pos) == 'I') {
// int
paramList.add("I");
pos++;
} else if (param.charAt(pos) == 'F') {
// float
paramList.add("F");
pos++;
} else {
throw new RuntimeException("the param has unsupported type:" + param);
}
param = param.substring(pos);
}
return paramList;
}
}