properties读取工具类设计
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类说明：
ClassPathPropsReader：class path properties reader
ClassNamePropsReader：按类名查找properties文件位置，properties文件名和类名相同、放置在同一个包下
PropsReaderFactory：ClassPathPropsReader静态工厂方法类
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主要代码：
package properties;import java.io.IOException;import java.util.Properties;/** * class path properties reader * * @author Mov * @version 1.0 Mov 2013-2-2 下午08:21:38 create * @see ClassNamePropsReader * @see PropsReaderFactory */public abstract class ClassPathPropsReader { private static Properties props; private void init() { if (props == null) { synchronized (this) { props = new Properties(); try { String filePath = getFilePath(); props.load(this.getClass().getClassLoader() .getResourceAsStream(filePath)); } catch (IOException e) { e.printStackTrace(); } } } } /** * 获取properties文件路径 * @return 返回格式如：com/XXX/YYY/Zzz.properties */ protected abstract String getFilePath(); @SuppressWarnings("unchecked") public final <T> T getProperty(String key, T defaultValue) { init(); try { String val = props.getProperty(key, null); Object ret = null; if (val == null || "".equals(val)) { ret = null; } else if (defaultValue instanceof String) { ret = val; } else if (defaultValue instanceof Integer) { ret = Integer.parseInt(val); } else if (defaultValue instanceof Boolean) { ret = val.toLowerCase().equals("true"); } else if (defaultValue instanceof Long) { ret = Long.parseLong(val); } else if (defaultValue instanceof Byte) { ret = Byte.parseByte(val); } else if (defaultValue instanceof Float) { ret = Float.parseFloat(val); } else if (defaultValue instanceof Double) { ret = Double.parseDouble(val); } else if (defaultValue instanceof Character) { ret = val.charAt(0); } else { ret = null; } return ret != null ? (T) ret : defaultValue; } catch (RuntimeException e) { return defaultValue; } }}?
package properties;import java.io.File;/** * properties文件名和类名相同、放置在同一个包下 * * <pre> * 如： * 类全名为a.b.c.Test * 则properties文件名为 a\b\c\Test.properties * * 此时可以直接继承{@link #ClassNamePropsReader} * </pre> * * @author Mov * @version 1.0 Mov 2013-2-2 下午08:23:13 create */public class ClassNamePropsReader extends ClassPathPropsReader { @Override protected String getFilePath() { String fullClassName = this.getClass().getCanonicalName(); return fullClassName.replace('.', File.separatorChar) + ".properties"; }}?
package properties;import java.util.HashMap;import java.util.Map;/** * ClassPathPropsReader静态工厂方法类 * * @author Mov * @version 1.0 Mov 2013-2-2 下午08:25:24 create */public class PropsReaderFactory { private static Map<Class<? extends ClassPathPropsReader>, ClassPathPropsReader> readers = new HashMap<Class<? extends ClassPathPropsReader>, ClassPathPropsReader>(); public static ClassPathPropsReader getInstance(Class<? extends ClassPathPropsReader> cls) { if (readers.get(cls) == null) { try { ClassPathPropsReader reader = cls.newInstance(); readers.put(cls, reader); } catch (InstantiationException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } } return readers.get(cls); }}?
测试：
package properties;import properties.xxx.yyy.HelloWorld;/** * * @author Mov * @version 1.0 Mov 2013-2-2 下午09:03:48 create */public class Test { public static void main(String[] args) { ClassPathPropsReader reader = PropsReaderFactory.getInstance(HelloWorld.class); String str0 = reader.getProperty("str0", "_____"); String str2 = reader.getProperty("str2", "_____"); System.out.println(str0); System.out.println(str2); int int0 = reader.getProperty("int0", -1); int int2 = reader.getProperty("int2", -1); System.out.println(int0); System.out.println(int2); boolean boolean0 = reader.getProperty("boolean0", Boolean.TRUE); boolean boolean2 = reader.getProperty("boolean2", Boolean.TRUE); System.out.println(boolean0); System.out.println(boolean2); char char0 = reader.getProperty("char0", '_'); System.out.println(char0); }}?
缺少的文件在附件中
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