[TDR Generic Table][Java SDK] Traverse Full Table Data

1. Interface Description

Traverse data in a specified table.

2. Version Requirements

This interface is provided in all versions without special requirements.

3. Preparations

Refer to Preparation document to complete the preparation before using this interface and create the following TDR Generic table.

Get the following information after the preparation. These details will be used by the SDK:

1. Directory server address list
2. App ID
3. App access password
4. Game zone ID
5. Table name

4. Example Code

Basic execution process of example code:

1. Create a client;
2. Create a request;
3. Send a request;
4. Process the response;
5. Destroy the client.

4.1 Example Code for Synchronous Call

import com.tencent.tcaplus.client.Client;
import com.tencent.tcaplus.client.ClientFactory;
import com.tencent.tcaplus.client.GenericTableTraverser;
import com.tencent.tcaplus.client.Record;
import com.tencent.tcaplus.client.Request;
import com.tencent.tcaplus.client.Response;
import com.tencent.tdr.tcaplus_protocol_cs.TcaplusProtocolCsConstants;

import java.util.ArrayList;
import java.util.List;

public class Example {

    public static void main(String[] arguments) {
        // 1. Prepare the environment information
        // 1.1. Directory server address list
        List<String> dirList = new ArrayList<String>();
        dirList.add("tcp://x.x.x.x:9999");
        dirList.add("tcp://y.y.y.y:9999");
        // 1.2. App ID
        int appId = 1;
        // 1.3. App password
        String appPassword = "****************";
        // 1.4. Table group ID
        int tableGroupId = 1;
        // 1.5. Table name
        String tableName = "test";

        // 2. Create a client
        Client client = ClientFactory.createClient(appId, tableGroupId, appPassword, dirList);
        try {
            // 3. Construct a request to read data according to the value of partial Key fields
            // 3.1. Create a scanner
            GenericTableTraverser traverser = client.getGenericTableTraverser(tableName);
            // 3.2. Add the Value field to be read
            traverser.addFieldName("typeid");
            traverser.addFieldName("Data");
            traverser.addFieldName("uname");
            // 3.3. Set the maximum amount of data that can be returned in a batch. Due to the large amount of data returned by scanning, it must be returned in batches.
            traverser.setLoadOptions(100);
            // 3.4. Set the maximum amount of data returned in total
            traverser.setTotalLimit(10000);

            // 4. Start the scanner
            Iterator<Record> iterator = traverser.start();

            // 5. Loop through iterators to get data until all data is read
            while (iterator.hasNext()) {
                Record result = iterator.next();
                // TODO: add code to process the return data
            }
        } finally {
            // 6. Destroy the client object
            ClientFactory.destroyClient(client);
        }
    }

4.2 Example Code for Asynchronous Call

import com.tencent.tcaplus.client.Client;
import com.tencent.tcaplus.client.ClientFactory;
import com.tencent.tcaplus.client.GenericTableTraverser;
import com.tencent.tcaplus.client.Record;
import com.tencent.tcaplus.client.Request;
import com.tencent.tcaplus.client.Response;
import com.tencent.tdr.tcaplus_protocol_cs.TcaplusProtocolCsConstants;

import java.util.ArrayList;
import java.util.List;

public class Example {

    public static void main(String[] arguments) {
        // 1. Prepare the environment information
        // 1.1. Directory server address list
        List<String> dirList = new ArrayList<String>();
        dirList.add("tcp://x.x.x.x:9999");
        dirList.add("tcp://y.y.y.y:9999");
        // 1.2. App ID
        int appId = 1;
        // 1.3. App password
        String appPassword = "****************";
        // 1.4. Table group ID
        int tableGroupId = 1;
        // 1.5. Table name
        String tableName = "test";

        // 2. Create a client
        Client client = ClientFactory.createClient(appId, tableGroupId, appPassword, dirList);
        try {
            // 3. Construct a request to read data according to the value of partial Key fields
            // 3.1. Create a scanner
            GenericTableTraverser traverser = client.getGenericTableTraverser(tableName);
            // 3.2. Add the Value field to be read
            traverser.addFieldName("typeid");
            traverser.addFieldName("Data");
            traverser.addFieldName("uname");
            // 3.3. Set the maximum amount of data that can be returned in a batch. Due to the large amount of data returned by scanning, it must be returned in batches.
            traverser.setLoadOptions(100);
            // 3.4. Set the maximum amount of data returned in total
            traverser.setTotalLimit(10000);

            CountDownLatch latch = new CountDownLatch(1);

            // 4. Start the scanner asynchronously and specify the return result processor
            traverser.startAsync(new Future() {

                @Override
                public void onResponse(Response response) {
                    // 5. Process the result
                    if (response.getResult() == 0) {
                        for (Record result : response.getRecordList()) {
                            // TODO: add code to process the data
                        }
                    }
                    if (traverser.isCompleted()) {
                        latch.countDown();
                    }
                }

            });

            latch.await();
        } finally {
            // 6. Destroy the client object
            ClientFactory.destroyClient(client);
        }
    }

5. Method Description for the User to Obtain the Traverser Object

Note: If there is an unlisted method to obtain the traverser object, it means that the method is invalid in the scenario of scanning data.

6. Traversal Object Method Description

Note: If there is an unlisted method to obtain the GenericTableTraverser object, it means that the method is invalid in the scenario of scanning data.

7. Method Description of Data Object Obtained from Data Iterator

Note: If there is an unlisted method to obtain the Record object, it means that the method is invalid in the scenario of scanning data.

8. FAQ

For details, see Meaning and Handling of Error Codes.

9. Other Reference Documents

[[TDR Generic Table][C++ SDK] Interface Description for Traversing Table Data](../../01C++_SDK/02Interface_Documents/13[Generic_Table]Traverse_Table_Data.md

[[TDR Generic Table] [Go SDK] Interface Description for Traversing Table Data](../../03Go_SDK/02Interface_Documents/13[Generic_Table]Traverse_Table_Data.md

[[TDR Generic Table] [MySQL Protocol Compatibility Interface] Interface Description for Traversing Full Table](../../04MySQL_Protocol_Compatibility_Interface/02Syntax_Description/05[Generic_Table]Traverse_Full_Table.md