文件读取工具类

该工具类是根据shiro工具类进行改写的。可以读取类路径下的文件、文件系统文件和网络文件。

maven

      <dependency>            <groupId>org.slf4j</groupId>            <artifactId>slf4j-log4j12</artifactId>            <version>1.7.2</version>        </dependency>

package com.utils.io;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStream;import java.net.URL;/** * Created by Administrator on 2017-05-13. */public class ResourceUtils {    private static final Logger log = LoggerFactory.getLogger(ResourceUtils.class);    public static final String CLASSPATH_PREFIX = "classpath:";    public static final String URL_PREFIX = "url:";    public static final String FILE_PREFIX = "file:";    private ResourceUtils() {    }    public static boolean hasResourcePrefix(String resourcePath) {        return resourcePath != null && (resourcePath.startsWith("classpath:") || resourcePath.startsWith("url:") || resourcePath.startsWith("file:"));    }    public static boolean resourceExists(String resourcePath) {        InputStream stream = null;        boolean exists = false;        try {            stream = getInputStreamForPath(resourcePath);            exists = true;        } catch (IOException var12) {            stream = null;        } finally {            if (stream != null) {                try {                    stream.close();                } catch (IOException var11) {                    ;                }            }        }        return exists;    }    public static InputStream getInputStreamForPath(String resourcePath) throws IOException {        InputStream is;        if (resourcePath.startsWith("classpath:")) {            is = loadFromClassPath(stripPrefix(resourcePath));        } else if (resourcePath.startsWith("url:")) {            is = loadFromUrl(stripPrefix(resourcePath));        } else if (resourcePath.startsWith("file:")) {            is = loadFromFile(stripPrefix(resourcePath));        } else {            is = loadFromFile(resourcePath);        }        if (is == null) {            throw new IOException("Resource [" + resourcePath + "] could not be found.");        } else {            return is;        }    }    private static InputStream loadFromFile(String path) throws IOException {        if (log.isDebugEnabled()) {            log.debug("Opening file [" + path + "]...");        }        return new FileInputStream(path);    }    private static InputStream loadFromUrl(String urlPath) throws IOException {        log.debug("Opening url {}", urlPath);        URL url = new URL(urlPath);        return url.openStream();    }    private static InputStream loadFromClassPath(String path) {        log.debug("Opening resource from class path [{}]", path);        return ResourcesUtilsBase.getResourceAsStream(path);    }    private static String stripPrefix(String resourcePath) {        return resourcePath.substring(resourcePath.indexOf(":") + 1);    }    public static void close(InputStream is) {        if (is != null) {            try {                is.close();            } catch (IOException var2) {                log.warn("Error closing input stream.", var2);            }        }    }}

package com.utils.io;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import java.io.InputStream; class ResourcesUtilsBase {    private static final Logger log = LoggerFactory.getLogger(ResourcesUtilsBase.class);    private static final ResourcesUtilsBase.ClassLoaderAccessor THREAD_CL_ACCESSOR = new ResourcesUtilsBase.ExceptionIgnoringAccessor() {        protected ClassLoader doGetClassLoader() throws Throwable {            return Thread.currentThread().getContextClassLoader();        }    };    private static final ResourcesUtilsBase.ClassLoaderAccessor CLASS_CL_ACCESSOR = new ResourcesUtilsBase.ExceptionIgnoringAccessor() {        protected ClassLoader doGetClassLoader() throws Throwable {            return ResourcesUtilsBase.class.getClassLoader();        }    };    private static final ResourcesUtilsBase.ClassLoaderAccessor SYSTEM_CL_ACCESSOR = new ResourcesUtilsBase.ExceptionIgnoringAccessor() {        protected ClassLoader doGetClassLoader() throws Throwable {            return ClassLoader.getSystemClassLoader();        }    };    public ResourcesUtilsBase() {    }    /**     *从类路径下获取资源     * @param name 类路径。如:config/jdbc.properties     * @return     */    public static InputStream getResourceAsStream(String name) {        InputStream is = THREAD_CL_ACCESSOR.getResourceStream(name);        if(is == null) {            if(log.isTraceEnabled()) {                log.trace("Resource [" + name + "] was not found via the thread context ClassLoader.  Trying the " + "current ClassLoader...");            }            is = CLASS_CL_ACCESSOR.getResourceStream(name);        }        if(is == null) {            if(log.isTraceEnabled()) {                log.trace("Resource [" + name + "] was not found via the current class loader.  Trying the " + "system/application ClassLoader...");            }            is = SYSTEM_CL_ACCESSOR.getResourceStream(name);        }        if(is == null && log.isTraceEnabled()) {            log.trace("Resource [" + name + "] was not found via the thread context, current, or " + "system/application ClassLoaders.  All heuristics have been exhausted.  Returning null.");        }        return is;    }    private abstract static class ExceptionIgnoringAccessor implements ResourcesUtilsBase.ClassLoaderAccessor {        private ExceptionIgnoringAccessor() {        }        public InputStream getResourceStream(String name) {            InputStream is = null;            ClassLoader cl = this.getClassLoader();            if(cl != null) {                is = cl.getResourceAsStream(name);            }            return is;        }        protected final ClassLoader getClassLoader() {            try {                return this.doGetClassLoader();            } catch (Throwable var2) {                if(ResourcesUtilsBase.log.isDebugEnabled()) {                    ResourcesUtilsBase.log.debug("Unable to acquire ClassLoader.", var2);                }                return null;            }        }        protected abstract ClassLoader doGetClassLoader() throws Throwable;    }    private interface ClassLoaderAccessor {        InputStream getResourceStream(String var1);    }}