Bean 生成器
这是一个java bean生成器，利用一个文本文件（不妨称为bean定义文件）生成java bean。

开发过程中我们可能会用到很多数据对象（值对象），大都被封装成一个bean。虽然各大

IDE都提供了方便生成这种数据bean的工具，但都是一步一步填对话框式的，不像这个，

这个可以在一个文件里定义多个Bean，一次生成所有bean。当然它也有局限性，目前只会

简单的生成private数据域和public 的setter、getter；并且不会替你导入必要的包。但尽管如此，

也能大大方便数据bean比较多，或bean字段比较多的应用。

bean定义文件（.bd）格式如下：

// 这是注释，以"//"打头。
// 用"#"表示bean名称。
// 注释不能和bean名称或数据字段写在同一行。
#MyBean1
int i
long l
String s

#MyBean2
String user
String pwd

#MyBean3
Object o
...

...



import java.io.*;
import java.util.*;


public class CreateBean {

private BufferedReader in;
private String inputFile;
private HashMap beans = new HashMap();
private static final char beanMark = #;

public CreateBean(String inputFileName) {
inputFile = inputFileName;
try {
in = new BufferedReader(new FileReader(inputFileName));
} catch (FileNotFoundException e) {
System.out.println("file " + inputFileName + " not found!");
e.printStackTrace();
}
}

public void generate() {
String ln = null;
String beanName = null;
ArrayList properties = new ArrayList();

try {
ln = in.readLine().trim(); // throw io excption

while (ln != null) {
if(
( ln.length() < 1 ) ||
( ln.startsWith("//") ) || // comments
( ln.charAt(0)!=beanMark && ln.split("\\s+").length!=2 )
){}
else if (ln.charAt(0) == beanMark) {
if (beanName != null) {
beans.put(beanName, properties); // save last bean to hashMap
}

properties = new ArrayList();

// gen new bean name
beanName = upperFirst(ln.substring(1));
System.out.println("bean: " + beanName);
}
else {
System.out.println("\t " + ln);
properties.add(ln);
}

ln = in.readLine();
if(ln==null){ // last bean
if (beanName != null) {
beans.put(beanName, properties);
}
}
else{
ln = ln.trim();
}
} //while

System.out.println( beans.size() + " beans tested ...");
dumpBeans();

} catch (IOException e) {
System.out.println("read file failed!");
} finally {
try {
if (in != null)
in.close();
} catch (IOException e2) {
System.out.println("close input file failed!");
e2.printStackTrace();
}
}

}

public static String upperFirst(String s) {
StringBuffer buf = new StringBuffer(s);
if (buf.charAt(0) >= a && buf.charAt(0) <= z) {
buf.setCharAt(0, (char)(buf.charAt(0) - 32));
}
return buf.toString();
}

private void dumpBeans() {
System.out.println("creating ...");

StringBuffer buf = null;
String key = null;
PrintWriter pw = null;
Iterator itr = null;
Set keySet = beans.keySet();

if(keySet!=null)
itr = keySet.iterator();

while (itr.hasNext()) {
buf = new StringBuffer();
key = (String) itr.next();
ArrayList l = (ArrayList) beans.get(key);
buf.append("public class ");
buf.append(key);
buf.append(" {\r\n\n");

// add properties
for (int i = 0; i < l.size(); i++) {
buf.append("\tprivate ");
buf.append((String) l.get(i));
buf.append(";\r\n");
}
buf.append("\r\n");

// add getter and setter
for (int i = 0; i < l.size(); i++) {
// getter
String item = (String) l.get(i); // like "int a"
String type = item.split("\\s+", 2)[0]; // tok needed!!!
String var = item.split("\\s+", 2)[1];
buf.append("\tpublic "+ type + " get");
buf.append(upperFirst(var));
buf.append("() {\r\n\t\treturn this.");
buf.append(var);
buf.append(";\r\n\t}\n");

//setter
buf.append("\tpublic void set");
buf.append(upperFirst(var));
buf.append("(" + type + " " + var + ") {\r\n\t\tthis.");
buf.append(var);
buf.append(" = ");
buf.append(var);
buf.append(";\r\n\t}\n");
}
buf.append("}\r\n");

//dump to a named file
try{
pw = new PrintWriter(
new BufferedWriter(
new FileWriter(key+".java")));
pw.write(buf.toString());
pw.close();

}catch(IOException e){
System.out.println("create java file failed!");
e.printStackTrace();
}

}

}

/********************************/

public static void main(String[] args) throws Exception {

if(args.length<1){
System.out.println("usage:");
System.out.println("\tjava CreateBean yourInputFileName");
System.out.println("where your input file should like this:");
System.out.println("#myBean1");
System.out.println("int field1");
System.out.println("long field2");
System.out.println("String filed3");
System.out.println("...\n");
System.out.println("#myBean2");
System.out.println("char field1");
System.out.println("Object field2");
System.out.println("...");
System.out.println("\n...");
return;
}
System.out.println("begin ...");
CreateBean cb = new CreateBean(args[0]);
cb.generate();
System.out.println("complete.");

}

}