Java转Delphi的工具类

最近有个项目需要用到Java中间层和Delphi客户端，中间层和客户端之间的交互用JSON；

大家都知道Java世界里存在着各种各样的实体类，而Delphi端也需要这些实体类的代码，当然通过JNI也是可以访问JAVA代码的，但是这样无疑会带来项目复杂度，因此写了这么个转换工具类。

调用方法：ClassUtil.TransforEntiyToDelphi( ClassUtil.getModelClasses("com.nbport") );

com.nbport是包名，其会扫描包下所有被标记为@Entity的类

1.实现了Java实体类转为Delphi实体类的功能

2.实现了由SuperObject直接映射成为Delphi实体类的功能；

代码很垃圾。。。有空再重构下

package com.nbport.ctos.framework.util;

import java.beans.PropertyDescriptor;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileFilter;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLDecoder;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

import javax.persistence.Entity;

import org.springframework.beans.BeanWrapper;
import org.springframework.beans.BeanWrapperImpl;

public class ClassUtil {

	private static Hashtable< Class<?>,Integer > useEntiy = new Hashtable< Class<?>,Integer >();
	
	private static final String NEWLINE = "\r\n";
	
	public static void TransforEntiyToDelphi(Set<Class<?>> set)
			throws IOException, InstantiationException, IllegalAccessException {
		for (Class<?> c : set) {
			useEntiy.clear();
			String className = GetDClassName(c);
			File file = new File(GetDUintName(c)+".pas");
			BufferedWriter out = new BufferedWriter(new OutputStreamWriter(
					new FileOutputStream(file)));
			BeanWrapper bw = new BeanWrapperImpl(c.newInstance());
			PropertyDescriptor[] pds = bw.getPropertyDescriptors();
			StringBuffer privateFieldString = new StringBuffer();
			StringBuffer publicFieldString = new StringBuffer();
			StringBuffer propertyString = new StringBuffer();
			StringBuffer methodImpString = new StringBuffer();
			StringBuffer createFromJson = new StringBuffer();
			StringBuffer destroyString = new StringBuffer(); 
			publicFieldString.append("\t")
					.append("constructor Create; overload;").append(NEWLINE);
			publicFieldString
					.append("\t")
					.append("constructor Create(obj : ISuperObject); overload;")
					.append(NEWLINE);
			publicFieldString
					.append("\t")
					.append("destructor Destroy; overload;")
					.append(NEWLINE);
			
			publicFieldString.append("\t")
					.append("procedure CreateFromJSON(obj : ISuperObject);")
					.append(NEWLINE);
			
			methodImpString.append("constructor ").append(className)
					.append(".").append("Create").append(";").append(NEWLINE);
			methodImpString.append("begin").append(NEWLINE).append("\t")
					.append("inherited Create;").append(NEWLINE).append("end;")
					.append(NEWLINE);
			
			methodImpString.append("constructor ").append(className)
					.append(".").append("Create(obj : ISuperObject);").append(NEWLINE);
			methodImpString.append("begin").append(NEWLINE).append("\t")
					.append("inherited Create;").append(NEWLINE).append("\t")
					.append("CreateFromJSON(obj);").append(NEWLINE)
					.append("end;").append(NEWLINE);
			
			methodImpString.append(GetDestoryString(destroyString, c));
			
			createFromJson
					.append("procedure ").append(className).append(".")
					.append("CreateFromJSON(obj : ISuperObject);").append(NEWLINE);
			if(IsNeedVarArray(c)){
				createFromJson.append("var").append(NEWLINE).append("i : Integer;").append(NEWLINE)
					.append("jsonArray : TSuperArray;").append(NEWLINE);
			}
			createFromJson.append("begin").append(NEWLINE);
			for (PropertyDescriptor pd : pds) {
				Method readMethod = pd.getReadMethod();
				Method writeMethod = pd.getWriteMethod();
				if (readMethod != null && writeMethod != null) {
					String fieldName = pd.getDisplayName();
					String fixedName = "F"
							+ fieldName.substring(0, 1).toUpperCase()
							+ fieldName.substring(1);
					privateFieldString.append("\t").append(fixedName)
							.append(" : ")
							.append(JToD(pd.getPropertyType(),readMethod))
							.append(";").append(NEWLINE);

					publicFieldString
							.append("\t")
							.append("procedure " + writeMethod.getName())
							.append("(")
							.append("const Value : "
									+ JToD(writeMethod
											.getParameterTypes()[0],readMethod))
							.append(")").append(";").append(NEWLINE);

					publicFieldString.append("\t")
							.append("function " + readMethod.getName())
							.append("() : ").append(JToD(readMethod.getReturnType(),readMethod))
							.append(";").append(NEWLINE);

					propertyString.append("\t").append("property ")
							.append(fieldName.substring(0, 1).toUpperCase()+ fieldName.substring(1)).append(" : ")
							.append(JToD(pd.getPropertyType(),readMethod))
							.append(" read ").append(readMethod.getName())
							.append(" write ").append(writeMethod.getName())
							.append(";").append(NEWLINE);

					methodImpString
							.append("procedure ")
							.append(className)
							.append(".")
							.append(writeMethod.getName())
							.append("(")
							.append("const Value : "
									+ JToD(writeMethod
											.getParameterTypes()[0],readMethod))
							.append(")").append(";").append(NEWLINE);

					methodImpString.append("begin").append(NEWLINE).append("\t")
							.append(fixedName).append(" := Value;")
							.append(NEWLINE).append("end;").append(NEWLINE);

					methodImpString.append("function ").append(className)
							.append(".").append(readMethod.getName())
							.append("() : ").append(JToD(readMethod.getReturnType(),readMethod))
							.append(";").append(NEWLINE);

					methodImpString.append("begin").append(NEWLINE).append("\t")
							.append("Result := ").append(fixedName).append(";")
							.append(NEWLINE).append("end;").append(NEWLINE);
					
					GetJsonConvertString(createFromJson,fieldName,fixedName,pd);
				}
			}
			out.write("unit "+GetDUintName(c)+";");
			out.newLine();
			out.write("interface");
			out.newLine();
			out.write("uses");
			out.newLine();
			StringBuffer useUnit = new StringBuffer();
			for (Map.Entry<Class<?>,Integer> entry:useEntiy.entrySet()) {
				String unitName = GetDUintName(entry.getKey());
				if (unitName.compareToIgnoreCase(GetDUintName(c))!=0) {
					useUnit.append(unitName).append(",");
				}
			}
			out.write(useUnit.length()==0?"\tClasses,SysUtils,Contnrs,SuperObject;"
					:"\tClasses,SysUtils,Contnrs,SuperObject,"+useUnit.substring(0,useUnit.length()-1)+";");
			out.newLine();
			String typeDefine = GetTypeDefine(c);
			out.write(typeDefine.length()==0?"":"\ttype"+NEWLINE+typeDefine);
			out.newLine();
			out.write("\ttype");
			out.newLine();
			out.write("\t\t" + className + " = class(TObject)");
			out.newLine();
			out.write("private");
			out.newLine();
			out.write(privateFieldString.toString());
			out.newLine();
			out.write("public");
			out.newLine();
			out.write(publicFieldString.toString());
			out.newLine();
			out.write(propertyString.toString());
			out.newLine();
			out.write("end;");
			out.newLine();
			out.write("implementation");
			out.newLine();
			out.write(methodImpString.toString());
			out.write(createFromJson.append("end;").append(NEWLINE).toString());
			out.newLine();
			out.write("end.");
			out.newLine();
			out.flush();
			out.close();
		}
	}

	private static boolean IsNeedVarArray(Class<?> c) throws InstantiationException, IllegalAccessException {
		BeanWrapper bw = new BeanWrapperImpl(c.newInstance());
		PropertyDescriptor[] pds = bw.getPropertyDescriptors();
		for (PropertyDescriptor pd:pds) {
			if(pd.getPropertyType().getSimpleName().compareToIgnoreCase("list")==0){
				Class<?> jClass = GetGenericTypeByGetMethod(pd.getReadMethod());
				if (IsEntiyClass(jClass)) {
					return true;
				}
			}
		}
		return false;
	}

	private static String GetTypeDefine(Class<?> c) throws InstantiationException, IllegalAccessException {
		BeanWrapper bw = new BeanWrapperImpl(c.newInstance());
		PropertyDescriptor[] pds = bw.getPropertyDescriptors();
		StringBuffer sb = new StringBuffer();
		for (PropertyDescriptor pd:pds) {
			if(pd.getPropertyType().getSimpleName().compareToIgnoreCase("list")==0){
				Class<?> jClass = GetGenericTypeByGetMethod(pd.getReadMethod());
				if (IsEntiyClass(jClass)) {
					sb.append("\t\t").append(GetDClassName(jClass)).append("Array = Array of ").append(GetDClassName(jClass)).append(";");
				}else {
					sb.append("\t\t").append(JToDBasic(jClass)).append("Array = Array of ").append(JToDBasic(jClass)).append(";");
				}
			}
		}
		return sb.toString();
	}

	public static Set<Class<?>> getModelClasses(String pack) {
		Set<Class<?>> set = getClasses(pack);
		Set<Class<?>> newSet = new LinkedHashSet<Class<?>>();
		for (Class<?> c : set) {
			if (IsEntiyClass(c)) {
				newSet.add(c);
			}
		}
		return newSet;
	}
	
	public static Set<Class<?>> getClasses(String pack) {
		// 第一个class类的集合
		Set<Class<?>> classes = new LinkedHashSet<Class<?>>();
		// 是否循环迭代
		boolean recursive = true;
		// 获取包的名字 并进行替换
		String packageName = pack;
		String packageDirName = packageName.replace('.', '/');
		// 定义一个枚举的集合 并进行循环来处理这个目录下的things
		Enumeration<URL> dirs;
		try {
			dirs = Thread.currentThread().getContextClassLoader()
					.getResources(packageDirName);
			// 循环迭代下去
			while (dirs.hasMoreElements()) {
				// 获取下一个元素
				URL url = dirs.nextElement();
				// 得到协议的名称
				String protocol = url.getProtocol();
				// 如果是以文件的形式保存在服务器上
				if ("file".equals(protocol)) {
					// 获取包的物理路径
					String filePath = URLDecoder.decode(url.getFile(), "UTF-8");
					// 以文件的方式扫描整个包下的文件 并添加到集合中
					findAndAddClassesInPackageByFile(packageName, filePath,
							recursive, classes);
				} else if ("jar".equals(protocol)) {
					// 如果是jar包文件
					// 定义一个JarFile
					JarFile jar;
					try {
						// 获取jar
						jar = ((JarURLConnection) url.openConnection())
								.getJarFile();
						// 从此jar包 得到一个枚举类
						Enumeration<JarEntry> entries = jar.entries();
						// 同样的进行循环迭代
						while (entries.hasMoreElements()) {
							// 获取jar里的一个实体 可以是目录 和一些jar包里的其他文件 如META-INF等文件
							JarEntry entry = entries.nextElement();
							String name = entry.getName();
							// 如果是以/开头的
							if (name.charAt(0) == '/') {
								// 获取后面的字符串
								name = name.substring(1);
							}
							// 如果前半部分和定义的包名相同
							if (name.startsWith(packageDirName)) {
								int idx = name.lastIndexOf('/');
								// 如果以"/"结尾 是一个包
								if (idx != -1) {
									// 获取包名 把"/"替换成"."
									packageName = name.substring(0, idx)
											.replace('/', '.');
								}
								// 如果可以迭代下去 并且是一个包
								if ((idx != -1) || recursive) {
									// 如果是一个.class文件 而且不是目录
									if (name.endsWith(".class")
											&& !entry.isDirectory()) {
										// 去掉后面的".class" 获取真正的类名
										String className = name.substring(
												packageName.length() + 1,
												name.length() - 6);
										try {
											// 添加到classes
											classes.add(Class
													.forName(packageName + '.'
															+ className));
										} catch (ClassNotFoundException e) {

										}
									}
								}
							}
						}
					} catch (IOException e) {
						// log.error("在扫描用户定义视图时从jar包获取文件出错");
						e.printStackTrace();
					}
				}
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
		return classes;
	}

	public static void findAndAddClassesInPackageByFile(String packageName,
			String packagePath, final boolean recursive, Set<Class<?>> classes) {
		// 获取此包的目录 建立一个File
		File dir = new File(packagePath);
		// 如果不存在或者 也不是目录就直接返回
		if (!dir.exists() || !dir.isDirectory()) {
			// log.warn("用户定义包名 " + packageName + " 下没有任何文件");
			return;
		}
		// 如果存在 就获取包下的所有文件 包括目录
		File[] dirfiles = dir.listFiles(new FileFilter() {
			// 自定义过滤规则 如果可以循环(包含子目录) 或则是以.class结尾的文件(编译好的java类文件)
			public boolean accept(File file) {
				return (recursive && file.isDirectory())
						|| (file.getName().endsWith(".class"));
			}
		});
		// 循环所有文件
		for (File file : dirfiles) {
			// 如果是目录 则继续扫描
			if (file.isDirectory()) {
				findAndAddClassesInPackageByFile(
						packageName + "." + file.getName(),
						file.getAbsolutePath(), recursive, classes);
			} else {
				// 如果是java类文件 去掉后面的.class 只留下类名
				String className = file.getName().substring(0,
						file.getName().length() - 6);
				try {
					classes.add(Thread.currentThread().getContextClassLoader()
							.loadClass(packageName + '.' + className));
				} catch (ClassNotFoundException e) {

				}
			}
		}
	}
	
	private static String GetDestoryString(StringBuffer sb,Class<?> jClass) throws InstantiationException, IllegalAccessException {
		BeanWrapper bw = new BeanWrapperImpl(jClass.newInstance());
		PropertyDescriptor[] pds = bw.getPropertyDescriptors();
		sb.append("destructor ").append(GetDClassName(jClass)).append(".Destroy;").append(NEWLINE);
		sb.append("var i:Integer;").append(NEWLINE);
		sb.append("begin").append(NEWLINE);
		sb.append("\t").append("inherited Destroy;").append(NEWLINE);
		for (PropertyDescriptor pd:pds) {
			Class<?> c = pd.getPropertyType();
			String fieldName = pd.getDisplayName();
			String fixedName = "F"
					+ fieldName.substring(0, 1).toUpperCase()
					+ fieldName.substring(1);
			if (c.getSimpleName().compareToIgnoreCase("list") == 0) {
				Class<?> gClass = GetGenericTypeByGetMethod(pd.getReadMethod());
				if (IsEntiyClass(gClass)) {
					sb.append("\t").append("for i:=0 to Length("+fixedName+")-1 do").append(NEWLINE);
					sb.append("\tbegin").append(NEWLINE);
					sb.append("\t\t").append(fixedName).append("[i].").append("Destroy;").append(NEWLINE);
					sb.append("\tend;").append(NEWLINE);
				}
			}else{
				if(IsEntiyClass(c)){
					sb.append("\t").append(fixedName).append(".Destroy;").append(NEWLINE);
				}
			}
		}
		return sb.append("end;").append(NEWLINE).toString();
	}
	
	private static String JToDBasic(Class<?> jClass) {
		if (jClass==null) {
			return "TObject";
		}
		if (IsEntiyClass(jClass)) {
			useEntiy.put(jClass, 1);
		}
		if (jClass.getSimpleName().compareToIgnoreCase("int") == 0
			|| jClass.getSimpleName().compareToIgnoreCase("long") == 0
			|| jClass.getSimpleName().compareToIgnoreCase("integer")==0) {
				return "Integer";
		}else if (jClass.getSimpleName().compareToIgnoreCase("double") == 0
				|| jClass.getSimpleName().compareToIgnoreCase("float") == 0) {
			return "Double";
		} else if (jClass.getSimpleName().compareToIgnoreCase("boolean") == 0) {
			return "Boolean";
		} else if (jClass.getSimpleName().compareToIgnoreCase("string") == 0
				|| jClass.getSimpleName().compareToIgnoreCase("date") == 0) {
			return "String";
		}
		return jClass.getSimpleName();
	}
	
	private static String JToD(Class<?> jClass,Method method) {
		if (jClass==null||method==null) {
			return "TObject";
		}
		if (IsEntiyClass(jClass)) {
			useEntiy.put(jClass, 1);
			return GetDClassName(jClass);
		}
		if (jClass.getSimpleName().compareToIgnoreCase("int") == 0
			|| jClass.getSimpleName().compareToIgnoreCase("long") == 0
			|| jClass.getSimpleName().compareToIgnoreCase("integer")==0) {
			return "Integer";
		}else if (jClass.getSimpleName().compareToIgnoreCase("double") == 0
				|| jClass.getSimpleName().compareToIgnoreCase("float") == 0) {
			return "Double";
		} else if (jClass.getSimpleName().compareToIgnoreCase("boolean") == 0) {
			return "Boolean";
		} else if (jClass.getSimpleName().compareToIgnoreCase("string") == 0
				|| jClass.getSimpleName().compareToIgnoreCase("date") == 0) {
			return "String";
		} else if (jClass.getSimpleName().compareToIgnoreCase("list") == 0) {
			Class<?> genericType = GetGenericTypeByGetMethod(method);
			if (IsEntiyClass(genericType)) {
				useEntiy.put(genericType, 1);
				return GetDClassName(genericType)+"Array";
			}else {
				return JToDBasic(genericType)+"Array";
			}
		}
		return jClass.getSimpleName();
	}

	public static Class<?> GetGenericTypeByGetMethod(Method method){ 
		ParameterizedType pt= (ParameterizedType)method.getGenericReturnType(); 
		if (pt!=null&&pt.getActualTypeArguments()!=null&&pt.getActualTypeArguments().length>0) {
			return (Class<?>)pt.getActualTypeArguments()[0];
		}
		return null; 
	}
	
	private static boolean IsEntiyClass(Class<?> jClass){
		return (jClass!=null&&jClass.getAnnotation(Entity.class)!=null);
	}
	
	private static String GetDUintName(Class<?> jClass) {
		return "U"+jClass.getSimpleName()+"Obj";
	}
	
	private static String GetDClassName(Class<?> jClass){
		return "T" + jClass.getSimpleName();
	}
	
	private static void GetJsonConvertString(StringBuffer sb,String fieldName,String fixedName,PropertyDescriptor pd){
		Class<?> jClass = pd.getPropertyType();
		sb.append("if obj['").append(fieldName).append("']").append("<>nil then").append(NEWLINE);
		sb.append("begin").append(NEWLINE);
		if (jClass.getSimpleName().compareToIgnoreCase("int") == 0
			|| jClass.getSimpleName().compareToIgnoreCase("long") == 0
			|| jClass.getSimpleName().compareToIgnoreCase("integer")==0) {
			sb.append("\t").append(fixedName).append(" := ").append("obj['").append(fieldName).append("']").append(".AsInteger();").append(NEWLINE);
		}else if (jClass.getSimpleName().compareToIgnoreCase("double") == 0
				|| jClass.getSimpleName().compareToIgnoreCase("float") == 0) {
			sb.append("\t").append(fixedName).append(" := ").append("obj['").append(fieldName).append("']").append(".AsDouble();").append(NEWLINE);
		}else if (jClass.getSimpleName().compareToIgnoreCase("boolean") == 0) {
			sb.append("\t").append(fixedName).append(" := ").append("obj['").append(fieldName).append("']").append(".AsBoolean();").append(NEWLINE);
		} else if (jClass.getSimpleName().compareToIgnoreCase("string") == 0
				|| jClass.getSimpleName().compareToIgnoreCase("date") == 0) {
			sb.append("\t").append(fixedName).append(" := ").append("obj['").append(fieldName).append("']").append(".AsString();").append(NEWLINE);
		} else if (jClass.getSimpleName().compareToIgnoreCase("list") == 0) {
			Class<?> genericType = GetGenericTypeByGetMethod(pd.getReadMethod());
			sb.append("\t").append("jsonArray := obj['").append(fieldName).append("']").append(".AsArray();").append(NEWLINE);
			sb.append("\t").append("setLength(").append(fixedName).append(",jsonArray.Length);").append(NEWLINE);
			sb.append("\t").append("for i:=0 to jsonArray.Length-1 do").append(NEWLINE);
			sb.append("\t").append("begin").append(NEWLINE);
			if (IsEntiyClass(genericType)){
				sb.append("\t\t").append(fixedName).append("[i] := ").append(GetDClassName(genericType))
					.append(".Create(").append("jsonArray.O[i]").append(");").append(NEWLINE);
			}else {
				sb.append("\t\t").append(fixedName).append("[i] := ").append("jsonArray.")
					.append(GetJsonBasicString(genericType)).append("[i]").append(");").append(NEWLINE);
			}
			sb.append("\tend;").append(NEWLINE);
		}else if(IsEntiyClass(jClass)){
			sb.append("\t").append(fixedName).append(" := ").append(GetDClassName(jClass)).append(".Create(").append("obj['"+fieldName+"']);").append(NEWLINE);
		}
		sb.append("end;").append(NEWLINE);
		return;
	}

	private static Object GetJsonBasicString(Class<?> jClass) {
		if (jClass.getSimpleName().compareToIgnoreCase("int") == 0
			|| jClass.getSimpleName().compareToIgnoreCase("long") == 0
			|| jClass.getSimpleName().compareToIgnoreCase("integer")==0) {
				return "I";
			}else if (jClass.getSimpleName().compareToIgnoreCase("double") == 0
					|| jClass.getSimpleName().compareToIgnoreCase("float") == 0) {
				return "D";
			}else if (jClass.getSimpleName().compareToIgnoreCase("boolean") == 0) {
				return "B";
			} else if (jClass.getSimpleName().compareToIgnoreCase("string") == 0
					|| jClass.getSimpleName().compareToIgnoreCase("date") == 0) {
				return "S";
			}
		return "S";
	}
}