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2.java getResourceAsStream方法
3.@Import({ AutoConfigurationImportSelector.class})
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ãã public class CompilerTest {
ãã public static void main(String[] args) throws Exception {
ãã String source = "public class Main { public static void main(String[] args) { System.out.println(\"Hello World!\");} }";
ãã JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
ãã StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, null);
ãã StringSourceJavaObject sourceObject = newCompilerTest.StringSourceJavaObject("Main", source);
ãã Iterable< extends JavaFileObject> fileObjects = Arrays.asList(sourceObject);
ãã CompilationTask task = compiler.getTask(null, fileManager, null,null, null, fileObjects);
ãã boolean result = task.call();
ãã if (result) {
ãã System.out.println("ç¼è¯æåã");
ãã }
ãã }
ãã
ãã static class StringSourceJavaObject extends SimpleJavaFileObject {
ãã
ãã private String content = null;
ãã public StringSourceJavaObject(String name, String content) throwsURISyntaxException {
ãã super(URI.create("string:///" + name.replace('.','/') + Kind.SOURCE.extension), Kind.SOURCE);
ãã this.content = content;
ãã }
ãã
ãã public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException {
ãã return content;
ãã }
ãã }
ãã }
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ãã private static double calculate(String expr) throws CalculationException {
ãã String className = "CalculatorMain";
ãã String methodName = "calculate";
ãã String source = "public class " + className
ãã + " { public static double " + methodName + "() { return " + expr +"; } }";
ãã //çç¥å¨æç¼è¯Javaæºä»£ç çç¸å ³ä»£ç ï¼åè§ä¸ä¸è
ãã boolean result = task.call();
ãã if (result) {
ãã ClassLoader loader = Calculator.class.getClassLoader();
ãã try {
ãã Class<?> clazz = loader.loadClass(className);
ãã Method method = clazz.getMethod(methodName, new Class<?>[] { });
ãã Object value = method.invoke(null, new Object[] { });
ãã return (Double) value;
ãã } catch (Exception e) {
ãã throw new CalculationException("å é¨é误ã");
ãã }
ãã } else {
ãã throw new CalculationException("é误ç表达å¼ã");
ãã }
ãã }
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java getResourceAsStream方法
J2SE中的getResourceAsStream用法有以下几种:
第一: 要加载的文件和.class文件在同一目录下,例如:com.x.y 下有类me.class ,源码用同时有资源文件myfile.xml
那么,应该有如下代码:
me.class.getResourceAsStream("myfile.xml");
第二:在me.class目录的法方法聚合app视频源码子目录下,例如:com.x.y 下有类me.class ,源码用同时在 com.x.y.file 目录下有资源文件myfile.xml
那么,应该有如下代码:
me.class.getResourceAsStream("file/myfile.xml");
第三:不在me.class目录下,法方法韩国快三源码也不在子目录下,源码用uu彩票源码例如:com.x.y 下有类me.class ,法方法同时在 com.x.file 目录下有资源文件myfile.xml
那么,应该有如下代码:
me.class.getResourceAsStream("/com/x/file/myfile.xml");
总结一下,源码用可能只是法方法两种写法
第一:前面有 “ / ”
“ / ”代表了工程的根目录,例如工程名叫做myproject,源码用“ / ”代表了myproject
me.class.getResourceAsStream("/com/x/file/myfile.xml");
第二:前面没有 “ / ”
代表当前类的法方法目录
me.class.getResourceAsStream("myfile.xml");
me.class.getResourceAsStream("file/myfile.xml");
注:
getResourceAsStream读取的文件路径只局限与工程的源文件夹中,包括在工程src根目录下,源码用以及类包里面任何位置,法方法动漫图网站源码但是源码用如果配置文件路径是在除了源文件夹之外的其他文件夹中时,该方法是法方法禅意花园视频源码用不了的。
@Import({ AutoConfigurationImportSelector.class})
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继ç»ç¹å¼loadFactoryæ¹æ³
```java
public static ListloadFactoryNames(Class factoryClass, @Nullable ClassLoaderclassLoader) {
//è·ååºå ¥çé®
String factoryClassName = factoryClass.getName();
return(List)loadSpringFactories(classLoader).getOrDefault(factoryClassName,Collections.emptyList());
}
private static Map>loadSpringFactories(@Nullable ClassLoader classLoader) {
MultiValueMap result =(MultiValueMap)cache.get(classLoader);
if (result != null) {
return result;
} else {
try {
//å¦æç±»å è½½å¨ä¸ä¸ºnullï¼åå 载类路å¾ä¸spring.factoriesæ件ï¼å°å ¶ä¸è®¾ç½®çé 置类çå ¨è·¯å¾ä¿¡æ¯å°è£ 为Enumeration类对象
Enumeration urls =classLoader != null ?classLoader.getResources("META-INF/spring.factories") :ClassLoader.getSystemResources("META-INF/spring.factories");
LinkedMultiValueMap result =new LinkedMultiValueMap();
//循ç¯Enumeration类对象ï¼æ ¹æ®ç¸åºçèç¹ä¿¡æ¯çæProperties对象ï¼éè¿ä¼ å ¥çé®è·åå¼ï¼å¨å°å¼åå²ä¸ºä¸ä¸ªä¸ªå°çå符串转å为Arrayï¼æ¹æ³resultéåä¸
while(urls.hasMoreElements()) {
URL url =(URL)urls.nextElement();
UrlResource resource = newUrlResource(url);
Properties properties =PropertiesLoaderUtils.loadProperties(resource);
Iterator var6 =properties.entrySet().iterator();
while(var6.hasNext()) {
Entry entry= (Entry)var6.next();
String factoryClassName= ((String)entry.getKey()).trim();
String[] var9 =StringUtils.commaDelimitedListToStringArray((String)entry.getValue());
int var =var9.length;
for(int var = 0;var < var; ++var) {
String factoryName= var9[var];
result.add(factoryClassName, factoryName.trim());
}
}
}
cache.put(classLoader, result);
return result;
```
ä¼å»è¯»åä¸ä¸ªsprin g.factoriesçæ件ï¼è¯»åä¸å°ä¼è¡¨è¿ä¸ªé误ï¼æ们继ç»æ ¹æ®ä¼çå°ï¼æç»è·¯å¾çé¿è¿æ ·ï¼èè¿ä¸ªæ¯springæä¾çä¸ä¸ªå·¥å ·ç±»
```java
public final class SpringFactoriesLoader {
public static final String FACTORIES_RESOURCE_LOCATION ="META-INF/spring.factories";
}
```
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