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一直在努力,还没想过要放弃...

Redis与Tomcat集群集成

在网站访问量急剧上升时,通常需要使用集群的方法进行横向扩展。
对于没有状态的应用来说,直接用nginx进行处理即可。
但对于有状态的应用来说,比如登录状态等,除了使用nginx进行扩展外,就需要考虑到Session共享的问题了。

大家知道可以用apache+tomcat来实现Session共享,但效率太低了,而且容易出错。
今天说的主要是用nginx+tomcat+redis+tomcat-redis-session-manager的方式实现共享。
原理比较简单:

1、tomcat-redis-session-manage扩展了
org.apache.catalina.valves.ValveBase;
org.apache.catalina.session.ManagerBase;
org.apache.catalina.session.StandardSession;
并通过Tomcat配置,替代了这几个类。

2、Set属性时,用session id作为key,将Tomcat的整个Session拆分为SessionSerializationMetadata+RedisSession然后序列化为byte[],存放到Redis。

3、Get属性时,用session id作为key,从Redis获取byte[],然后反序列化为SessionSerializationMetadata+RedisSession,供Tomcat使用。

配置也很简单:
1、从github下载源码tomcat-redis-session-manager

2、用gradle进行编译

#master分支下面,要把signing段和uploadArchives段删掉,才能正常编译
#release就不需要了
gradle build

3、将三个Jar包拷贝到Tomcat的lib文件夹下

#%TOMCAT_HOME%/lib
tomcat-redis-session-manager-master-2.0.0.jar
commons-pool2-2.2.jar
jedis-2.5.2.jar

4、修改context.xml配置文件,新增下面内容就搞定咯

<!--%TOMCAT_HOME%/conf/context.xml-->
  <Valve className="com.orangefunction.tomcat.redissessions.RedisSessionHandlerValve" />
  <Manager className="com.orangefunction.tomcat.redissessions.RedisSessionManager" 
  host="localhost" port="6379" database="0" maxInactiveInterval="60"/>

好处是:不需要修改应用
坏处是:要耗费一定的时间来(序列化+保存到Redis)、(反序列化+从Redis读取)。

eXistDB简单通讯12(HTTP_SOAP)

  • 保存文件
  • 取回文件
  • 查询

1、QueryFileSOAP.java

package com.neohope.existdb.test;

import org.exist.soap.Query;
import org.exist.soap.QueryResponse;
import org.exist.soap.QueryService;
import org.exist.soap.QueryServiceLocator;

import java.net.URL;
import java.nio.charset.Charset;

public class QueryFileSOAP {
    public static void QueryXML(String xquery, String user, String pwd) throws Exception {
        QueryService service = new QueryServiceLocator();
        Query query = service.getQuery(new URL("http://localhost:8080/exist/services/Query"));
        String sessionId = query.connect("neotest", "neotest");

        byte[] queryData = xquery.getBytes(Charset.forName("UTF-8"));
        QueryResponse resp = query.xquery( sessionId, queryData );
        System.out.println( "found: " + resp.getHits() );
        if(resp.getHits() == 0) {
            return;
        }
        else {
            //get 10 results
            byte[][] hits = query.retrieveData(sessionId, 1, 10,
                    true, false, "elements").getElements();
            for (int i = 0; i < hits.length; i++) {
                System.out.println(new String(hits[i], "UTF-8"));
            }
        }

        query.disconnect(sessionId);
    }

    public static void main(String args[]) throws Exception {
        String user = "neotest";
        String pwd = "neotest";
        String query ="for $name in collection('/db/CDA')/ClinicalDocument/recordTarget/patientRole/patient/name \n" +
                "return \n" +
                "<name>{$name}</name> ";
        QueryXML(query, user, pwd);
    }
}

eXistDB简单通讯11(HTTP_SOAP)

  • 保存文件
  • 取回文件
  • 查询

1、GetFileSOAP.java

package com.neohope.existdb.test;

import org.exist.soap.Query;
import org.exist.soap.QueryService;
import org.exist.soap.QueryServiceLocator;

import java.net.URL;


public class GetFileSOAP {
    public static void GetXML(String fileId, String user, String pwd) throws Exception {
        QueryService service = new QueryServiceLocator();
        Query query = service.getQuery(new URL("http://localhost:8080/exist/services/Query"));
        String session = query.connect(user, pwd);

        byte[] data = query.getResourceData(session,
                "/db/CDA/"+fileId,
                true, false, false);
        System.out.println(new String(data, "UTF-8"));
        query.disconnect(session);
    }

    public static void main(String args[]) throws Exception {
        String user = "neotest";
        String pwd = "neotest";
        GetXML("入院患者护理评估单01.xml",user,pwd);
    }
}

eXistDB简单通讯10(HTTP_SOAP)

  • 保存文件
  • 取回文件
  • 查询

1、SaveFileSOAP.java

package com.neohope.existdb.test;

import org.exist.soap.*;

import java.io.BufferedReader;
import java.io.FileReader;
import java.net.URL;
import java.nio.charset.Charset;

public class SaveFileSOAP {
    public static void SaveXML(String xmlFilePath, String user, String pwd) throws Exception {
        AdminService adminService = new AdminServiceLocator();
        Admin admin = adminService.getAdmin(new URL("http://localhost:8080/exist/services/Admin"));
        String session = admin.connect("neotest", "neotest");

        BufferedReader f = new BufferedReader(new FileReader(xmlFilePath));
        String line;
        StringBuffer xml = new StringBuffer();
        while ((line = f.readLine()) != null)
            xml.append(line);
        f.close();

        admin.store(session, xml.toString().getBytes(Charset.forName("UTF-8")), "UTF-8", "/db/CDA/入院患者护理评估单02.xml", true);
        admin.disconnect(session);
    }

    public static void main( String[] args ) throws Exception {
        String user = "neotest";
        String pwd = "neotest";
        SaveXML("PATH_TO_FILE\\入院患者护理评估单02.xml", user, pwd);
    }
}

eXistDB简单通讯09(HTTP_REST)

  • 保存文件
  • 取回文件
  • 查询

1、QueryFileHTTP.java

package com.neohope.existdb.test;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.Charset;

public class QueryFileHTTP {
    public static void QueryXML(String query) throws IOException {
        URL url = new URL("http://localhost:8080/exist/rest/db/CDA");
        HttpURLConnection connect = (HttpURLConnection) url.openConnection();
        connect.setRequestProperty("Content-Type", "application/xml");
        connect.setRequestMethod("POST");
        connect.setDoOutput(true);

        OutputStream os = connect.getOutputStream();
        os.write(query.getBytes(Charset.forName("UTF-8")));
        connect.connect();

        BufferedReader is = new BufferedReader(new InputStreamReader(connect.getInputStream()));
        String line;
        while((line = is.readLine()) != null)
            System.out.println(line);
    }

    public static void main(String[] args) throws IOException {
        String query ="<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
                "<query xmlns=\"http://exist.sourceforge.net/NS/exist\" start=\"1\" max=\"10\" cache=\"no\">\n";
        query +="<text><![CDATA[\n" +
                "for $name01 in /ClinicalDocument/recordTarget/patientRole/patient/name \n" +
                "return \n" +
                "<name>{$name01}</name> \n" +
                "]]></text> \n";
        query +="<properties> \n";
        query +="<property name=\"indent\" value=\"yes\"/> \n";
        query +="<property name=\"encoding\" value=\"UTF-8\"/> \n";
        query +="</properties> \n";
        query +="</query>";
        System.out.println(query);
        QueryXML(query);
    }
}

eXistDB简单通讯08(HTTP_REST)

  • 保存文件
  • 取回文件
  • 查询

1、GetFileHTTP.java

package com.neohope.existdb.test;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;


public class GetFileHTTP {
    public static void GetXML(String fileId) throws IOException {
        URL url = new URL("http://localhost:8080/exist/rest/db/CDA/" + fileId);
        System.out.println("GET file from " + url.toString());

        HttpURLConnection connect = (HttpURLConnection) url.openConnection();
        connect.setRequestMethod("GET");
        connect.connect();
        System.out.println("Result:");

        BufferedReader bis = new BufferedReader(new InputStreamReader(connect.getInputStream()));
        String line;
        while ((line = bis.readLine()) != null) {
            System.out.println(line);
        }
    }

    public static void main(String[] args) throws IOException {
        GetXML("入院患者护理评估单01.xml");
    }
}

eXistDB简单通讯07(HTTP_REST)

  • 保存文件
  • 取回文件
  • 查询

1、SaveFileHTTP.java

package com.neohope.existdb.test;

//apache的base64会多一个换行符
//import org.apache.ws.commons.util.Base64;
//import com.sun.org.apache.xerces.internal.impl.dv.util.Base64;
import com.sun.xml.internal.messaging.saaj.util.Base64;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class SaveFileHTTP {
    public static void SaveXML(String inFileName, String fileId) throws IOException {
        URL url = new URL("http://localhost:8080/exist/rest/db/CDA/" + fileId);
        System.out.println("Save file to " + url.toString());

        HttpURLConnection connect = (HttpURLConnection) url.openConnection();
        connect.setRequestMethod("PUT");
        connect.setDoOutput(true);
        connect.setRequestProperty("Content-Type", "application/xml");
        String userCredentials = "neotest:neotest";
        String basicAuth = "Basic " + new String(new Base64().encode(userCredentials.getBytes()));
        System.out.println(basicAuth);
        connect.setRequestProperty ("Authorization", basicAuth);

        File file = new File(inFileName);
        InputStream is = new FileInputStream(file);
        OutputStream os = connect.getOutputStream();

        byte[] buf = new byte[1024];
        int c;
        while ((c = is.read(buf)) > -1) {
            os.write(buf, 0, c);
        }
        os.flush();
        os.close();
        System.out.println("Statuscode " + connect.getResponseCode()
                + " (" + connect.getResponseMessage() + ")");
    }

    public static void main(String[] args) throws IOException {
        SaveXML("D:\\MyProjects\\IDEA14\\TestExistDB\\XMLFiles\\医惠\\入院患者护理评估单01.xml", "入院患者护理评估单01.xml");
    }
}

eXistDB简单通讯06(RPC)

  • 保存文件
  • 取回文件

1、GetFileRPC.java

package com.neohope.existdb.test;

import org.apache.xmlrpc.XmlRpcException;
import org.apache.xmlrpc.client.XmlRpcClient;
import org.apache.xmlrpc.client.XmlRpcClientConfigImpl;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URL;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Vector;

public class GetFileRPC {
    public static void GetXML(String documentId, String user, String pwd) throws Exception {
        String uri = "http://localhost:8080/exist/xmlrpc";
        XmlRpcClient client = new XmlRpcClient();
        XmlRpcClientConfigImpl config = new XmlRpcClientConfigImpl();
        config.setServerURL(new URL(uri));
        config.setBasicUserName(user);
        config.setBasicPassword(pwd);
        client.setConfig(config);

        HashMap<String, String> options = new HashMap<String, String>();
        options.put("indent", "yes");
        options.put("encoding", "UTF-8");
        options.put("expand-xincludes", "yes");
        options.put("process-xsl-pi", "no");

        Vector<Object> params = new Vector<Object>();
        params.addElement(documentId);
        params.addElement(options);
        String xml = (String)
                client.execute("getDocumentAsString", params);
        System.out.println(xml);
    }

    public static void GetXMLChuncked(String documentId, String outPath, String user, String pwd) throws IOException, XmlRpcException {
        String url = "http://localhost:8080/exist/xmlrpc";

        XmlRpcClient client = new XmlRpcClient();
        XmlRpcClientConfigImpl config = new XmlRpcClientConfigImpl();
        config.setServerURL(new URL(url));
        config.setBasicUserName(user);
        config.setBasicPassword(pwd);
        client.setConfig(config);

        Hashtable<String, String> options = new Hashtable<String, String>();
        options.put("indent", "no");
        options.put("encoding", "UTF-8");

        Vector<Object> params = new Vector<Object>();
        params.addElement(documentId);
        params.addElement(options);

        FileOutputStream fos = new FileOutputStream(outPath);
        HashMap<?, ?> ht = (HashMap<?, ?>) client.execute("getDocumentData", params);
        int offset = ((Integer) ht.get("offset")).intValue();
        byte[] data = (byte[]) ht.get("data");
        String handle = (String) ht.get("handle");
        fos.write(data);

        while (offset != 0) {
            params.clear();
            params.addElement(handle);
            params.addElement(new Integer(offset));

            ht = (HashMap<?, ?>) client.execute("getNextChunk", params);
            data = (byte[]) ht.get("data");
            offset = ((Integer) ht.get("offset")).intValue();
            fos.write(data);
        }
        fos.close();
    }

    public static void main(String args[]) throws Exception {
        String user = "neotest";
        String pwd = "neotest";
        //GetXML("/db/CDA/入院患者护理评估单05.xml", user, pwd);
        GetXMLChuncked("/db/PNG/兔子.png","兔子1.png", user, pwd);
    }
}

eXistDB简单通讯05(RPC)

  • 保存文件
  • 取回文件

1、SaveFileRPC.java

package com.neohope.existdb.test;

import org.apache.xmlrpc.client.XmlRpcClient;
import org.apache.xmlrpc.client.XmlRpcClientConfigImpl;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.InputStream;
import java.net.URL;
import java.util.Vector;

public class SaveFileRPC {
    public static void SaveXML(String xmlFilePath, String user, String pw) throws Exception {
        String url = "http://localhost:8080/exist/xmlrpc";
        String path = "/db/CDA/入院患者护理评估单05.xml";

        XmlRpcClient client = new XmlRpcClient();
        XmlRpcClientConfigImpl config = new XmlRpcClientConfigImpl();
        config.setServerURL(new URL(url));
        config.setBasicUserName(user);
        config.setBasicPassword(pw);
        client.setConfig(config);

        BufferedReader f = new BufferedReader(new FileReader(xmlFilePath));
        String line;
        StringBuffer xml = new StringBuffer();
        while ((line = f.readLine()) != null)
            xml.append(line);
        f.close();

        Vector<Object> params = new Vector<Object>();
        params.addElement(xml.toString());
        params.addElement(path);
        params.addElement(new Integer(0));
        Boolean result = (Boolean) client.execute("parse", params);

        if (result.booleanValue())
            System.out.println("document stored.");
        else
            System.out.println("could not store document.");
    }

    public static void SaveXMLChuncked(String xmlFilePath, String user, String pwd) throws Exception {
        String url = "http://localhost:8080/exist/xmlrpc";
        String path = "/db/PNG/兔子.png";

        XmlRpcClient client = new XmlRpcClient();
        XmlRpcClientConfigImpl config = new XmlRpcClientConfigImpl();
        config.setServerURL(new URL(url));
        config.setBasicUserName(user);
        config.setBasicPassword(pwd);
        client.setConfig(config);

        Vector<Object> params = new Vector<Object>();
        String handle = null;
        InputStream fis = new FileInputStream(xmlFilePath);
        byte[] buf = new byte[4096];
        int len;
        while ((len = fis.read(buf)) > 0) {
            params.clear();
            if (handle != null) {
                params.addElement(handle);
            }
            params.addElement(buf);
            params.addElement(new Integer(len));
            handle = (String) client.execute("upload", params);
        }
        fis.close();

        params.clear();
        params.addElement(handle);
        params.addElement(path);
        params.addElement(new Boolean(true));
        params.addElement("image/png");
        Boolean result = (Boolean) client.execute("parseLocal", params); // exceptions

        if (result.booleanValue())
            System.out.println("document stored.");
        else
            System.out.println("could not store document.");
    }

    public static void main(String args[]) throws Exception {
        String user = "neotest";
        String pwd = "neotest";
        SaveXML("PATH_TO_FILE\\入院患者护理评估单05.xml", user, pwd);
        //SaveXMLChuncked("D:\\MyProjects\\IDEA14\\TestExistDB\\XMLFiles\\兔子.png", user, pwd);
    }
}

eXistDB简单通讯04

  • 保存文件
  • 取回文件
  • 查询
  • 嵌套查询

1、Base.java

package com.neohope.existdb.test;

import org.exist.util.serializer.SAXSerializer;
import org.exist.util.serializer.SerializerPool;

import javax.xml.transform.OutputKeys;
import java.io.OutputStreamWriter;
import java.util.Properties;

public class Base {
    protected final static String URI = "xmldb:exist://localhost:8080/exist/xmlrpc";
    protected final static String driver = "org.exist.xmldb.DatabaseImpl";
    protected static  Class<?> cl = null;

    static{
        try {
            cl = Class.forName(driver);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

    protected static SAXSerializer getSAXSerializer()
    {
        Properties outputProperties = new Properties();
        outputProperties.setProperty(OutputKeys.INDENT, "yes");
        SAXSerializer serializer = (SAXSerializer) SerializerPool.getInstance().borrowObject(SAXSerializer.class);
        serializer.setOutput(new OutputStreamWriter(System.out), outputProperties);
        return serializer;
    }

    protected static void releaseSAXSerializer(SAXSerializer serializer) {
        SerializerPool.getInstance().returnObject(serializer);
    }
}

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