项目总结

--------------日志使用

1.maven依赖

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
    <version>1.7.25</version>
</dependency>
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.7.25</version>
</dependency>

2.代码案例

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class TestClassName {
    private static final String name="itXiaoBai";
    private static final Logger logger=LoggerFactory.getLogger(TestClassName.class);

    public static void main(String[] args) {
        logger.info("this is: {}",name);
    }
}

2018-12-03 21:53:17,461 INFO [test.TestClassName] - this is: itXiaoBai

Process finished with exit code 0

--------------@Date--pojo的set/get方法

1.maven依赖

<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.16.20</version>
</dependency>

2.代码案例

---------------HTTP获取URL中的内容&&IOUtils直接将流toString成字符串

1.maven依赖

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.4</version>
</dependency>

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.5</version>
</dependency>

2.代码案例

import org.apache.commons.io.IOUtils;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.SystemDefaultHttpClient;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.InputStream;

public class GetDateByURL {

    private static final Logger logger=LoggerFactory.getLogger(GetDateByURL.class);

    public static void main(String[] args) throws IOException {
        String url="https://blog.csdn.net/qq_38617531";
        HttpGet httpGet = new HttpGet(url);
        CloseableHttpResponse response = new SystemDefaultHttpClient().execute(httpGet);
        InputStream content = response.getEntity().getContent();
        String string = IOUtils.toString(content);
        logger.info("content:{}",string);
    }
}

---------解析json字符串

1.maven依赖

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.8.2</version>
</dependency>

2.代码案例

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 解析json字符串
 */
public class AnalyzeJson {
    private static final Logger logger=LoggerFactory.getLogger(AnalyzeJson.class);

    public static void main(String[] args) {
        String jsonStr="{
" +
                "  "beans" : [ {
" +
                "    "name" : "java.lang:type=OperatingSystem",
" +
                "    "modelerType" : "sun.management.OperatingSystemImpl",
" +
                "    "OpenFileDescriptorCount" : 289,
" +
                "    "MaxFileDescriptorCount" : 4096,
" +
                "    "CommittedVirtualMemorySize" : 2829778944,
" +
                "    "TotalSwapSpaceSize" : 1073737728,
" +
                "    "FreeSwapSpaceSize" : 408305664,
" +
                "    "ProcessCpuTime" : 85530000000,
" +
                "    "FreePhysicalMemorySize" : 89407488,
" +
                "    "TotalPhysicalMemorySize" : 1028235264,
" +
                "    "SystemCpuLoad" : 1.0,
" +
                "    "ProcessCpuLoad" : 0.0,
" +
                "    "AvailableProcessors" : 1,
" +
                "    "Version" : "2.6.32-642.el6.x86_64",
" +
                "    "Arch" : "amd64",
" +
                "    "SystemLoadAverage" : 1.36,
" +
                "    "Name" : "Linux",
" +
                "    "ObjectName" : "java.lang:type=OperatingSystem"
" +
                "  } ]
" +
                "}";
        JsonObject jsonObject = new JsonParser().parse(jsonStr).getAsJsonObject();
        double systemCpuLoad = jsonObject.getAsJsonArray("beans")
                .get(0)
                .getAsJsonObject()
                .get("SystemCpuLoad")
                .getAsDouble();
        logger.info("systemCpuLoad:{}",systemCpuLoad);
    }
}

-----------------------加载xml配置文件

1.maven依赖

<dependency>
    <groupId>dom4j</groupId>
    <artifactId>dom4j</artifactId>
    <version>1.6.1</version>
</dependency>

2.部分代码案例

test.xml

<?xml version="1.0" encoding="utf-8"?>
<tasks>
    <task>
        <name>cpuload</name>
        <type>hdfs</type>
        <period>3</period>
        <class>task.hdfs.CpuLoadTask</class>
    </task>
</tasks>

//加载配置文件
SAXReader reader = new SAXReader();
InputStream inputStream = App.class.getClassLoader().getResourceAsStream("test.xml");
//表示是task.xml
Document document = reader.read(inputStream);
Element root = document.getRootElement();

List<Element> childElements = root.elements();
for (Element child : childElements) {
    String period = child.element("period").getTextTrim();
    String className = child.element("class").getTextTrim();
    String type = child.element("type").getTextTrim();
    String name = child.element("name").getTextTrim();

    //通过反射机制   实例化对象
    MonitorTask instance = (MonitorTask) Class.forName(className).newInstance();

    //传入configuration,初始化
    Configuration conf = new SystemConfiguration();
    conf.setProperty("period", Long.valueOf(period));
    conf.setProperty("type", type);
    conf.setProperty("name", name);
    instance.init(conf);

-----------定时调度线程池

1.代码案例

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class ScheduledExecutorTest {
    private  ScheduledExecutorService scheduExec;
    public long start;

    ScheduledExecutorTest(){
        this.scheduExec =  Executors.newScheduledThreadPool(15);
        this.start = System.currentTimeMillis();
    }

    public void timer(){
        scheduExec.scheduleAtFixedRate(new Runnable() {
            public void run() {
                System.out.println("timer invoked .....");
            }
            //开始时间，间隔，时间类型
            /**
             * 2000:表示 2秒之后开始
             * 5000：表示 5秒执行一次
             * TimeUnit.MILLISECONDS：表示以毫秒为单位
             */
        },2000,5000,TimeUnit.MILLISECONDS);
    }

    public static void main(String[] args) {
        ScheduledExecutorTest test = new ScheduledExecutorTest();
        test.timer();
    }
}

------------通过加载配置文件，加载配置项

1.配置文件---kafka.properties

bootstrap.servers=192.168.10.3:9092
acks=all
retries=3
batch.size=5000000
linger.ms=6
buffer.memory=33554432
compression.type=gzip
key.serializer=org.apache.kafka.common.serialization.StringSerializer
value.serializer=org.apache.kafka.common.serialization.StringSerializer
auto.create.topics.enable=true

2.代码案例

import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.Producer;
import org.apache.kafka.clients.producer.ProducerRecord;

import java.io.IOException;
import java.util.Properties;

public class KafkaUtil {
    private static Producer<String, String> producer = null;

    static {
        Properties properties = new Properties();
        try {
            //通过加载配置文件，加载配置项
            properties.load(KafkaUtil.class.getClassLoader().getResourceAsStream("kafka.properties"));
            producer = new KafkaProducer<String, String>(properties);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void send(String content, String topic) {
        producer.send(new ProducerRecord<String, String>(topic, "", content));
    }
}

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