RT，前段時間讓做一個自動生成的DEMO，然，網上的不明甚以，故摘此篇，部分內容來自網際網路，算是一個大的總結。

這個demo實現的是在web頁面輸入表名列來自動生成一些常用基本的類。

TemplateUtil 類

獲取模板檔案的資訊，並對生成的java檔案的命名及存放路徑進行處理

注：basicAction類是action基類，是讀取現有檔案並做一定出來實現自動生成更改。

<span style="white-space:pre">	</span>private String project = null;// 專案名
	List fileName = new ArrayList();// 模板檔名
	private String tempPath = null;// 模板檔案存放路徑

	public TemplateUtil(String url) {
		setProject(url);
		setTempPath(url);
		setFileName();
	}

	public void setProject(String url) {
		project=url;
	}

	public void setTempPath(String tempPath) {
			this.tempPath = tempPath + "/src/template";
	}

	public String getTempPath() {
		return tempPath;
	}

	public List getFileName() {
		return fileName;
	}

	public void setFileName() {
		File filePath = new File(tempPath);
		if (filePath.isDirectory()) {
			File[] files = filePath.listFiles();
			for (File file : files) {
				fileName.add(file.getName());
			}
		}
	}

	public String getProject() {
		return project;
	}

	public String getSavePath(String type, String project, String className) {
		String newJavaFile = null;
		if (type.equalsIgnoreCase("dao")) {
			newJavaFile = project + "/src/dao/" + className
					+ "Dao.java";
		} else if (type.equalsIgnoreCase("daoImpl")) {
			newJavaFile = project + "/src/dao/impl/" + className
					+ "DaoImpl.java";
		} else if (type.equalsIgnoreCase("service")) {
			newJavaFile = project + "/src/service/" + className
					+ "Service.java";
		} else if (type.equalsIgnoreCase("serviceImpl")) {
			newJavaFile = project + "/src/service/impl/"
					+ className + "ServiceImpl.java";
		} else if (type.equalsIgnoreCase("entity")) {
			newJavaFile = project + "/src/model/"
					+ className + ".java";
		}else if (type.equalsIgnoreCase("entityHbm")) {
			newJavaFile = project + "/src/model/"
					+ className + ".hbm.xml";
		}else if (type.equalsIgnoreCase("action")) {
			String tblname=className.substring(3);	//去掉tbl的類名
			tblname=tblname.substring(0, 1).toUpperCase()+tblname.substring(1);
			newJavaFile = project + "/src/action/"
					+ tblname + "Action.java";
		}else if (type.equalsIgnoreCase("list")) {
			newJavaFile = project + "/WebRoot/WEB-INF/"
					 + "list.jsp";
		}else if (type.equalsIgnoreCase("add")) {
			newJavaFile = project + "/WebRoot/WEB-INF/"
					 + "add.jsp";
		}else if (type.equalsIgnoreCase("detail")) {
			newJavaFile = project + "/WebRoot/WEB-INF/"
					 + "detail.jsp";
		}else if (type.equalsIgnoreCase("edit")) {
			newJavaFile = project + "/WebRoot/WEB-INF/"
					 + "edit.jsp";
		}else if (type.equalsIgnoreCase("basicAction")) {
			 newJavaFile = project + "/src/action/"
					 + "BasicAction.java";
			 String data=readFileByLines(newJavaFile);	//讀取basicAction檔案
			 String ftlurl = project + "/src/template/basicAction.ftl";
			 wirteFileByLines(ftlurl,data);	//寫ftl模板檔案
		}else{
			newJavaFile="";
		}
		
		return new String(newJavaFile);
	}
	
	/**
	 * 根據傳入的表名生成model模型層
	 * @return	{@link Boolean} 
	 * @param date		當前日期
	 */
	@SuppressWarnings({ "static-access", "unchecked" })
	public void createOneEntity(AutoStartTableEntity aste,String url) {
		TemplateUtil tu = new TemplateUtil(url);
		// 模板名
		List<String> tempNameList = tu.getFileName();
		String className = aste.getTableName();
		Map map = new HashMap();
		map.put("name", className.toLowerCase());	//全小寫
		map.put("Name", className)	;
		map.put("NAME", className.toUpperCase());	//全大寫
		map.put("list", aste.getTableColumn());
		map.put("author", "作者");
		map.put("ps", "表名");
		map.put("date","2015");
		String tblname=className.substring(3);	//去掉tbl的類名
		map.put("tblname", tblname.toLowerCase());	//全小寫action類名
		map.put("tblName", tblname.substring(0, 1).toUpperCase()+tblname.substring(1));

		for (int j = 0; j < tempNameList.size(); j++) {
			String tempName = tempNameList.get(j);
			String type = tempName.substring(0, tempName.lastIndexOf("."));
			String newJavaFile = null;
			newJavaFile = tu.getSavePath(type, url, className);
			if(newJavaFile.equals("")){
				continue;
			}
			try {
					SpringTemplateUnits.templateAppend(tempName, newJavaFile,
							map, tu.getTempPath());
					System.out.println("已建立"+className);
			} catch (IOException e) {
				e.printStackTrace();
			} catch (TemplateException e) {
				e.printStackTrace();
			}
		}
	}
	/**
	 * 讀basicAction檔案返回字串
	 * @param filestr
	 * @return
	 */
	 public String readFileByLines(String filestr) {
	        BufferedReader reader = null;
	        String str="";
	        try {
	            System.out.println("以行為單位讀取檔案內容，一次讀一整行：");
	            reader = new BufferedReader(new InputStreamReader(new FileInputStream(filestr),"UTF-8"));
	            String tempString = null;
	            int line = 1;
	            // 一次讀入一行，直到讀入null為檔案結束
	            while ((tempString = reader.readLine()) != null) {
	            	tempString+="\r\n";
	                // 顯示行號
	            	if(tempString.equals("\t//自動生成表\r\n")){
	            		tempString+="\
 
[email protected](name =  ${Name}Service.${NAME}_SERVICE_IMPL)\r\n";
	            		tempString+="\tprotected ${Name}Service ${tblname}ser;\r\n";
	            	}
	            	if(tempString.equals("//自動生成匯入區域\r\n")){
	            		tempString+="import service.${Name}Service;\r\n";
	            	}
	                System.out.println("line " + line + ": " + tempString);
	                str+=tempString;
	                line++;
	            }
	            reader.close();
	        } catch (IOException e) {
	            e.printStackTrace();
	        } finally {
	            if (reader != null) {
	                try {
	                    reader.close();
	                } catch (IOException e1) {
	                }
	            }
	        }
	        return str;
	    }
	 /**
	  * 寫ftl模板檔案
	  * @param filestr
	  * @param data
	  */
	 public void wirteFileByLines(String filestr,String data) {
		 try {
			 File file =new File(filestr);
			 if(file.exists()){
				 file.delete();
			 }
			 OutputStreamWriter write = new OutputStreamWriter(new FileOutputStream(file),"UTF-8");
			 BufferedWriter bufferWritter = new BufferedWriter(write);
			 bufferWritter.write(data);
			 bufferWritter.close();
		 } catch (IOException e) {
			 // TODO Auto-generated catch block
			 e.printStackTrace();
		 }
		 System.out.println("File Wirte Done");
	 }
 

該檔案提供生成java檔案的介面

<span style="white-space:pre">	</span>public static String pageEncoding = "UTF-8";

	@SuppressWarnings("unchecked")
	public static boolean templateAppend(String ftlName, String targetFileName,
			Map map, String relPath) throws IOException, TemplateException {
		init(ftlName, targetFileName, map, relPath);
		return true;
	}

	@SuppressWarnings("unchecked")
	public static void init(String ftl, String targetName, Map map,
			String relPath) throws IOException, TemplateException {
		Configuration freemarkerCfg = new Configuration();
		freemarkerCfg.setDirectoryForTemplateLoading(new File(relPath));
		Locale ss=Locale.getDefault();
		freemarkerCfg.setEncoding(Locale.getDefault(), pageEncoding);
		Template template = freemarkerCfg.getTemplate(ftl, pageEncoding);
		template.setEncoding("UTF-8");
		File temp = new File(targetName);
		String dir = targetName.substring(0, targetName.lastIndexOf("/") + 1);
		File dirs = new File(dir);
		if (!dirs.exists()) {
			dirs.mkdirs();
		}
		Writer out = new BufferedWriter(new OutputStreamWriter(
				new FileOutputStream(temp), pageEncoding));
		template.process(map, out);
		out.flush();
		out.close();
	}
 

<prop key="hibernate.hbm2ddl.auto">update</prop>

entity.ftl

package model;

import java.io.Serializable;
import java.util.Date;
import javax.persistence.Column;  
import javax.persistence.Entity;  
import javax.persistence.GeneratedValue;  
import javax.persistence.GenerationType;  
import javax.persistence.Id;  
import javax.persistence.Table; 

@Entity  
@Table(name="${NAME}")  
@SuppressWarnings("serial")
public class ${Name} implements Serializable {
	
	 private static final long serialVersionUID = 1L;  
	
	
	<#list list as item>
	private ${item.colType} ${item.colName};
	</#list> 
	
	
	<#list list as item>
	
	<#if  item.colName="id">
	@Id  
    @GeneratedValue(strategy=GenerationType.IDENTITY)  
    <#elseif item.colName!="id"&&item.colLong="">
    @Column(name="${item.colName}",nullable = ${item.colNull} )  
    <#else>
    @Column(name="${item.colName}",length=${item.colLong},nullable = ${item.colNull})  
	</#if>
	public ${item.colType} get${item.colUPName}() {
		return ${item.colName};
	}
	public void set${item.colUPName}(${item.colType} ${item.colName}) {
		this.${item.colName} = ${item.colName};
	}
	</#list> 
	
	
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
	<class name="www.pdwy.model.${Name}" table="${NAME}">
		<id name="id" type="java.lang.Integer">
			<column name="ID" />
			<generator class="native" />
		</id>
		<#list list as item>
		<#if  item.colName!="id"&&item.colLong="">
		<property name="${item.colName}" type="${item.colAllType}">
			<column name="${item.colUPERName}" />
		</property>
		<#elseif item.colName!="id"&&item.colLong!="">
		<property name="${item.colName}" type="${item.colAllType}">
			<column name="${item.colUPERName}"  length="${item.colLong}" />
		</property>
		</#if>
		</#list> 
		
	</class>
	
</hibernate-mapping>

眾所周知，jsp一般需要使用到el表示式，而我們的模板中也恰恰使用到el表示式，在生成你的jsp過程中，freemarker會把你jsp中el表示式當做模板中的來使用，這樣就會出現錯誤。如何避免那？把它當做一個普通的字串就好。

使用${r""}格式來轉換。如：${r"${name}"} 看起來很好用不是嗎？

有的時候會碰到需要使用到模板自動生成的欄位再加上jsp固定的字串，這怎麼來實現？${r""} 同樣支援拼接。如：${r"${"}${tblname}${r"."}${item.colName}${r"}"}  看起來很複雜吧.......

在上述類中使用的了我自建立的工具類或者說模型類，它用來記錄在網頁上所填的表的資訊如：列名等等。

AutoStartTableEntity表模型類

	private String tableName;	//表名
	private List<AutoStartColumnEntity> tableColumn;	//表列
	
	public AutoStartTableEntity() {
	}

	public AutoStartTableEntity(String tableName,
			List<AutoStartColumnEntity> tableColumn) {
		this.tableName = tableName;
		this.tableColumn = tableColumn;
	}
	
	public String getTableName() {
		return tableName;
	}
	public void setTableName(String tableName) {
		this.tableName = tableName;
	}
	public List<AutoStartColumnEntity> getTableColumn() {
		return tableColumn;
	}
	public void setTableColumn(List<AutoStartColumnEntity> tableColumn) {
		this.tableColumn = tableColumn;
	}
	

	private String colName;	//列明
	private String colType;	//列型別
	private String colUPName;  //首字母大寫列名
	private String colUPERName;  //全大寫列名
	private String colLong;	//列長度
	private String colAllType;	//列全限定型別
	private String colNull;		//可否為空
	private String colJspName;		//jsp所用列描述名
	public AutoStartColumnEntity() {
	}

	public AutoStartColumnEntity(String colName, String colType) {
		setColName(colName);
		setColType(colType);
		setColUPName();
	}
	
	public String getColName() {
		return colName;
	}
	public void setColName(String colName) {
		this.colName = colName.toLowerCase();
	}
	
	public String getColType() {
		return colType;
	}
	public void setColType(String colType) {
		this.colType = colType;
		/**
		 * 原用於資料庫
		if(colType.equals("nvarchar")||colType.equals("varchar")||colType.equals("nchar")||colType.equals("char"))
			this.colType="String";
		if(colType.equals("datetime")){
			this.colType="Date";
		}	
		*/	
	}

	public String getColUPName() {
		return colUPName;
	}
	public void setColUPName() {
		this.colUPName=this.colName.substring(0,1).toUpperCase()+this.colName.substring(1);
	}

	public String getColLong() {
		return colLong;
	}

	public void setColLong(String colLong) {
		this.colLong = colLong;
	}


	public String getColUPERName() {
		return colUPERName;
	}

	public void setColUPERName() {
		this.colUPERName=this.colName.toUpperCase();
	}

	public String getColAllType() {
		return colAllType;
	}

	public void setColAllType() {
		this.colAllType = "java.lang."+colType;
		if(colType.equals("Date")){
			this.colAllType="java.util.Date";
		}
	}

	public String getColNull() {
		return colNull;
	}

	public void setColNull(String colNull) {
		this.colNull = colNull;
	}
	public void setColNull() {
		if(this.colNull==null||this.colNull.equals("")){
			this.colNull="false";
		}
	}

	public String getColJspName() {
		return colJspName;
	}

	public void setColJspName(String colJspName) {
		this.colJspName = colJspName;
	}

這是我action所做的操作。

	public String autoPrint() {
		//獲取要生成本地專案所在目錄
		String url=super.getParameter("url");
		TemplateUtil tu = new TemplateUtil(url);
		List<AutoStartColumnEntity> astee=new ArrayList<AutoStartColumnEntity>();
		//必要預製操作
		for (AutoStartColumnEntity col : aste.getTableColumn()) {
			if(col!=null){
				col.setColUPERName();
				col.setColUPName();
				col.setColAllType();
				col.setColNull();
				astee.add(col);
			}
		}
		aste.setTableColumn(astee);
		tu.createOneEntity(aste,url);
		return SUCCESS;
	}

最後上張頁面圖吧