關於java的eagle的信息

本文目錄一覽：

• 1、java對文件名的幾個操作，獲取文件擴展名，去掉擴展名
• 2、anm.java:36: 錯誤: eagle不是抽象的, 並且未覆蓋aif中的抽象方法climbtree() class eagle extends anima
• 3、kafka-eagle安裝踩坑
• 4、java編寫Animal類
• 5、java 怎麼用命令進入指定的目錄
• 6、一道JAVA題，在線等答案，求高手幫忙~

java對文件名的幾個操作，獲取文件擴展名，去掉擴展名

/*

 * Java文件操作 獲取文件擴展名

 *

 *  Created on: 2011-8-2

 *      Author: blueeagle

 */

    public static String getExtensionName(String filename) { 

        if ((filename != null)  (filename.length()  0)) { 

            int dot = filename.lastIndexOf(‘.’); 

            if ((dot -1)  (dot  (filename.length() – 1))) { 

                return filename.substring(dot + 1); 

            } 

        } 

        return filename; 

    } 

/*

 * Java文件操作 獲取不帶擴展名的文件名

 *

 *  Created on: 2011-8-2

 *      Author: blueeagle

 */

    public static String getFileNameNoEx(String filename) { 

        if ((filename != null)  (filename.length()  0)) { 

            int dot = filename.lastIndexOf(‘.’); 

            if ((dot -1)  (dot  (filename.length()))) { 

                return filename.substring(0, dot); 

            } 

        } 

        return filename; 

    }

anm.java:36: 錯誤: eagle不是抽象的, 並且未覆蓋aif中的抽象方法climbtree() class eagle extends anima

你的eagle類實現了aif接口，但是沒有重寫aif接口中的climbtree方法，cat類也是，沒有重寫aif接口中的fly方法，接口中的方法是必須全部被實現類重寫的

kafka-eagle安裝踩坑

1.遇到的第一個坑是啟動eagle失敗，查看logs/error.log和ke_console.out才知道是虛擬機內存不足，java虛擬機需要1G內存，而虛擬機本身才有1G

解決辦法：直接修改虛擬機內存

2.JMXConnector報錯，在kafka下面的kafka-server-start.sh文件里添加 jmx端口9999

3.mysql服務器連接一直報錯

java編寫Animal類

//接口的定義

interface Animal {

public void bark();

public void fly();

}

//老鷹類

class Eagle implements Animal {

public void bark() {

System.out.println(“老鷹叫”);

}

public void fly() {

System.out.println(“老鷹飛”);

}

}

//鴿子類

class Pigeon implements Animal{

public void bark() {

System.out.println(“鴿子叫”);

}

public void fly() {

System.out.println(“鴿子飛”);

}

}

//測試類

public class Test{

public static void main(String[] args){

Animal pigeon = new Pigeon();

Animal eagle = new Eagle();

pigeon.bark();

pigeon.fly();

eagle.bark();

eagle.fly();

}

}

如果還有什麼疑問..請百度Hi我.. 我會進一步的為你解答..

java 怎麼用命令進入指定的目錄

這個跟java沒關係，完全是dos命令

在dos里輸入 c: 回車，就到C盤了，其他類似

如果C盤下有abc文件夾，輸入cd abc 就可以進去了，cd就是進入文件夾的命令

cd..是退回到上一層目錄

cd/ 是退回到根目錄

一道JAVA題，在線等答案，求高手幫忙~

public class Test {

public static void main(String[] args) {

IBird chicken1 = new Chicken(“Chicken 1”, “Red”, 3.5F);

IBird chicken2 = new Chicken(“Chicken 1”, “Green”, 11.5F);

IBird chicken3 = new Chicken(“Chicken 1”, “Blue”, 7.5F);

IBird eagle1 = new Eagle(“Eagle 1”, “Black”, 100F);

IBird eagle2 = new Eagle(“Eagle 2”, “White”, 35F);

System.out.println(“Chicken 1 can reach 10 height? ” + chicken1.isReachable(10));

System.out.println(“Chicken 2 can reach 10 height? ” + chicken2.isReachable(10));

System.out.println(“Chicken 3 can reach 10 height? ” + chicken3.isReachable(10));

System.out.println(“Eagle 1 can reach 10 height? ” + eagle1.isReachable(10));

System.out.println(“Eagle 2 can reach 10 height? ” + eagle2.isReachable(10));

if(chicken1.isReachable(10F)){

chicken1.printBirdInformation();

}

if(chicken2.isReachable(10F)){

chicken2.printBirdInformation();

}

if(chicken3.isReachable(10F)){

chicken3.printBirdInformation();

}

if(eagle1.isReachable(10F)){

eagle1.printBirdInformation();

}

if(eagle2.isReachable(10F)){

eagle2.printBirdInformation();

}

}

}

interface IBird{

public void setName(String name);

public void setColor(String color);

public void setMaxFlyingHeight(float height);

public boolean isReachable(float height);

public void printBirdInformation();

}

class Chicken implements IBird{

private String name;

private String color;

private float maxFlyingHeight;

private int eggs;

public Chicken(String name, String color, float maxFlyingHeight){

this.name = name;

this.color = color;

this.maxFlyingHeight = maxFlyingHeight;

}

public int getEggs() {

return eggs;

}

public void setEggs(int eggs) {

this.eggs = eggs;

}

public boolean isReachable(float height) {

return height = maxFlyingHeight;

}

public void printBirdInformation() {

System.out.println(“Chicken’s information: name: ” + this.name + “, color: ” + this.color);

}

public void setColor(String color) {

this.color = color;

}

public void setMaxFlyingHeight(float height) {

this.maxFlyingHeight = height;

}

public void setName(String name) {

this.name = name;

}

}

class Eagle implements IBird{

private String name;

private String color;

private float maxFlyingHeight;

private double flyingDistance;

public Eagle(String name, String color, float maxFlyingHeight){

this.name = name;

this.color = color;

this.maxFlyingHeight = maxFlyingHeight;

}

public double getFlyingDistance() {

return flyingDistance;

}

public void setFlyingDistance(double flyingDistance) {

this.flyingDistance = flyingDistance;

}

public boolean isReachable(float height) {

return height = maxFlyingHeight;

}

public void printBirdInformation() {

System.out.println(“Eagle’s information: name: ” + this.name + “, color: ” + this.color);

}

public void setColor(String color) {

this.color = color;

}

public void setMaxFlyingHeight(float height) {

this.maxFlyingHeight = height;

}

public void setName(String name) {

this.name = name;

}

}