IO绠€浠?- Java IO缂栫▼ – 椋炴壃瀛﹂櫌.pdf 寤栭洩宄扮殑java鏁欑▼绫诲瀷锛?span class=”info”>鏂囨。(.pdf)澶у皬锛?span class=”info”>236KB鏃堕棿锛?span class=”info”>2019-01-20 18:31:19鏉ユ簮锛?span class=”info”>鐧惧害缃戠洏鐩綍锛?span class=”info”>/寤栭洩宄扮殑java鏁欑▼/6-Java IO缂栫▼/1-IO鍩虹鏌ョ湅鍒嗕韩鏂囦欢。
下列Java代码中的变量a、b、c分别在内存的__存储区存放？class A {private String a = “aa”;public boolean methodB {String b = “bb”;final String c = “cc”;}}堆区、栈区、栈区。
package cn.starry.gangchat.utils;23 import java.io.ByteArrayOutputStream;4 import java.io.IOException;5 import java.io.InputStream;67 public class StreamUtils {8 public static String streamToString(InputStream in) {9 String result = “”;10 try {11 // 创建一个字节数组写入流12 ByteArrayOutputStream out = new ByteArrayOutputStream;13 byte buffer = new byte[1024];14 int length = 0;15 while ((length = in.read(buffer)) != -1) {16 out.write(buffer, 0, length);17 out.flush;18 }19 result = new String(out.toByteArray, “utf-8”);20 out.close;21 } catch (IOException e) {22 e.printStackTrace;23 }24 return result;25 }26 }StreamUtils.java。
Java中常用的类，包，接口。class: ‘Date’,’System’,’Calender’,’Math’,’ArrayList’,’HashMap’package: ‘java.lang’,’java.util’,’java.io’,’java.sql’,’java.net’interface: ‘Collection’,’Map’,’List’,’Runnable’,’Callable。
package IO;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.io.Serializable;import sun.print.resources.serviceui;@SuppressWarnings(“serial”)class Book implements Serializable{private String title;private Double price;private transient String content;//瞬时 不会被序列化public void setTitle(String title) {this.title = title;}public String getTitle {return title;}public void setPrice(Double price) {this.price = price;}public Double getPrice {return price;}public void setContent(String content) {this.content = content;}public String getContent {return content;}@Overridepublic String toString {return “Book [title=” + title + “, price=” + price + “, content=” + content + “]”;}}public class SerializableDemo {public static void main(String args) throws IOException, ClassNotFoundException {ser;//dser;}/** 序列化*/public static void ser throws FileNotFoundException, IOException{Book book = new Book;book.setPrice(12.8);book.setTitle(“admin”);ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(new File(“E:” + File.separator + “person.ser”)));oos.writeObject(book);oos.close;}/** 反序列化*/public static void dser throws FileNotFoundException, IOException, ClassNotFoundException{ObjectInputStream ois = new ObjectInputStream(new FileInputStream(new File(“E:” + File.separator + “person.ser”)));Book per = (Book) ois.readObject;ois.close;System.out.println(per);}}transient 关键字修饰的属性不会被序列化6.IO的设计模式（装饰者模式 Decorator Pattern）。
Windows：C:\conf\default.propertiesLinux：/User/admin/conf/default.properties//先获取getClass，再通过getResourceAsStream可以获取任意的资源文件try(InputStream input = getClass.getResourceAsStream(“/default.properties”)){if(input != null){//如果资源文件在classpath未找到，会返回null}}public class Main {public static void main(String args) throws IOException {String data1 = {“setting.properties”,//正确路径”/com/testList/setting.properties”,//正确路径”/com/setting.properties”,//错误路径”src/main/java/com/setting.properties”,//错误路径};for(String data:data1){getProperty(data);}String data2 = {“Person.txt”,//正确路径”/com/testList/Person.txt”,//正确路径”/com/List/Person.txt”,//错误路径”/src/main/java/com/testList/Person.txt”,//错误路径};for(String data:data2){getText(data);}}static void getProperty(String data) throws IOException{try(InputStream input = Main.class.getResourceAsStream(data)) {if(input != null){System.out.println(data+”文件已读取”);Properties props = new Properties;props.load(input);System.out.println(“url=”+props.getProperty(“url”));System.out.println(“name=”+props.getProperty(“name”));}else{System.out.println(data+”文件不存在”);}}}static void getText(String data) throws IOException{try(InputStream input = Main.class.getResourceAsStream(data)){if(input != null){System.out.println(data+”文件已读取”);BufferedReader reader = new BufferedReader(new InputStreamReader(input));//BufferedReader有readline方法可以读取第一行文本System.out.println(reader.readLine);}else{System.out.println(data+”文件不存在”);}。
System.out.println(“数据:【” + new String(data, 0, foot) + “】”);。
System.out.println(“数据:【” + new String(data, 0, len) + “】”);。
