org.springframework.integration.jdbc.metadata.JdbcMetadataStore Maven / Gradle / Ivy
/*
* Copyright 2017 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.integration.jdbc.metadata;
import javax.sql.DataSource;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.dao.EmptyResultDataAccessException;
import org.springframework.integration.metadata.ConcurrentMetadataStore;
import org.springframework.integration.metadata.MetadataStore;
import org.springframework.jdbc.core.JdbcOperations;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.Assert;
/**
* Implementation of {@link MetadataStore} using a relational database via JDBC.
* SQL scripts to create the necessary tables are packaged as
* org/springframework/integration/jdbc/schema-*.sql,
* where * is the target database type.
*
* The transaction management is required to use this {@link MetadataStore}.
*
* @author Bojan Vukasovic
* @author Artem Bilan
*
* @since 5.0
*/
public class JdbcMetadataStore implements ConcurrentMetadataStore, InitializingBean {
/**
* Default value for the table prefix property.
*/
public static final String DEFAULT_TABLE_PREFIX = "INT_";
private final JdbcOperations jdbcTemplate;
private volatile String tablePrefix = DEFAULT_TABLE_PREFIX;
private volatile String region = "DEFAULT";
private String getValueQuery = "SELECT METADATA_VALUE FROM %SMETADATA_STORE WHERE METADATA_KEY=? AND REGION=?";
private String getValueForUpdateQuery = "SELECT METADATA_VALUE FROM %SMETADATA_STORE WHERE METADATA_KEY=? AND REGION=? FOR UPDATE";
private String replaceValueQuery = "UPDATE %SMETADATA_STORE SET METADATA_VALUE=? WHERE METADATA_KEY=? AND METADATA_VALUE=? AND REGION=?";
private String replaceValueByKeyQuery = "UPDATE %SMETADATA_STORE SET METADATA_VALUE=? WHERE METADATA_KEY=? AND REGION=?";
private String removeValueQuery = "DELETE FROM %SMETADATA_STORE WHERE METADATA_KEY=? AND REGION=?";
private String putIfAbsentValueQuery = "INSERT INTO %SMETADATA_STORE(METADATA_KEY, METADATA_VALUE, REGION) "
+ "SELECT ?, ?, ? FROM %SMETADATA_STORE WHERE METADATA_KEY=? AND REGION=? HAVING COUNT(*)=0";
@Override
public void afterPropertiesSet() throws Exception {
this.getValueQuery = String.format(this.getValueQuery, this.tablePrefix);
this.getValueForUpdateQuery = String.format(this.getValueForUpdateQuery, this.tablePrefix);
this.replaceValueQuery = String.format(this.replaceValueQuery, this.tablePrefix);
this.replaceValueByKeyQuery = String.format(this.replaceValueByKeyQuery, this.tablePrefix);
this.removeValueQuery = String.format(this.removeValueQuery, this.tablePrefix);
this.putIfAbsentValueQuery = String.format(this.putIfAbsentValueQuery, this.tablePrefix, this.tablePrefix);
}
/**
* Instantiate a {@link JdbcMetadataStore} using provided dataSource {@link DataSource}.
* @param dataSource a {@link DataSource}
*/
public JdbcMetadataStore(DataSource dataSource) {
this(new JdbcTemplate(dataSource));
}
/**
* Instantiate a {@link JdbcMetadataStore} using provided jdbcOperations {@link JdbcOperations}.
* @param jdbcOperations a {@link JdbcOperations}
*/
public JdbcMetadataStore(JdbcOperations jdbcOperations) {
Assert.notNull(jdbcOperations, "'jdbcOperations' must not be null");
this.jdbcTemplate = jdbcOperations;
}
/**
* Public setter for the table prefix property.
* This will be prefixed to all the table names before queries are
* executed. Defaults to {@link #DEFAULT_TABLE_PREFIX}.
* @param tablePrefix the tablePrefix to set
*/
public void setTablePrefix(String tablePrefix) {
Assert.notNull(tablePrefix, "'tablePrefix' must not be null");
this.tablePrefix = tablePrefix;
}
/**
* A unique grouping identifier for all messages persisted with this store.
* Using multiple regions allows the store
* to be partitioned (if necessary) for different purposes.
* Defaults to DEFAULT.
* @param region the region name to set
*/
public void setRegion(String region) {
Assert.hasText(region, "Region must not be null or empty.");
this.region = region;
}
@Override
@Transactional
public String putIfAbsent(String key, String value) {
Assert.notNull(key, "'key' cannot be null");
Assert.notNull(value, "'value' cannot be null");
while (true) {
//try to insert if does not exists
int affectedRows = tryToPutIfAbsent(key, value);
if (affectedRows > 0) {
//it was not in the table, so we have just inserted it
return null;
}
else {
//value should be in table. try to return it
try {
return this.jdbcTemplate.queryForObject(this.getValueQuery, String.class, key, this.region);
}
catch (EmptyResultDataAccessException e) {
//somebody deleted it between calls. try to insert again (go to beginning of while loop)
}
}
}
}
private int tryToPutIfAbsent(String key, String value) {
return this.jdbcTemplate.update(this.putIfAbsentValueQuery,
ps -> {
ps.setString(1, key);
ps.setString(2, value);
ps.setString(3, this.region);
ps.setString(4, key);
ps.setString(5, this.region);
});
}
@Override
@Transactional
public boolean replace(String key, String oldValue, String newValue) {
Assert.notNull(key, "'key' cannot be null");
Assert.notNull(oldValue, "'oldValue' cannot be null");
Assert.notNull(newValue, "'newValue' cannot be null");
int affectedRows = this.jdbcTemplate.update(this.replaceValueQuery,
ps -> {
ps.setString(1, newValue);
ps.setString(2, key);
ps.setString(3, oldValue);
ps.setString(4, this.region);
});
return affectedRows > 0;
}
@Override
@Transactional
public void put(String key, String value) {
Assert.notNull(key, "'key' cannot be null");
Assert.notNull(value, "'value' cannot be null");
while (true) {
//try to insert if does not exist, if exists we will try to update it
int affectedRows = tryToPutIfAbsent(key, value);
if (affectedRows == 0) {
//since value is not inserted, means it is already present
try {
//lock row for updating
this.jdbcTemplate.queryForObject(this.getValueForUpdateQuery, String.class, key, this.region);
}
catch (EmptyResultDataAccessException e) {
//if there are no rows with this key, somebody deleted it in between two calls
continue; //try to insert again from beginning
}
//lock successful, so - replace
this.jdbcTemplate.update(this.replaceValueByKeyQuery,
ps -> {
ps.setString(1, value);
ps.setString(2, key);
ps.setString(3, this.region);
});
}
return;
}
}
@Override
@Transactional
public String get(String key) {
Assert.notNull(key, "'key' cannot be null");
try {
return this.jdbcTemplate.queryForObject(this.getValueQuery, String.class, key, this.region);
}
catch (EmptyResultDataAccessException e) {
//if there are no rows with this key, return null
return null;
}
}
@Override
@Transactional
public String remove(String key) {
Assert.notNull(key, "'key' cannot be null");
String oldValue;
try {
//select old value and lock row for removal
oldValue = this.jdbcTemplate.queryForObject(this.getValueForUpdateQuery, String.class, key, this.region);
}
catch (EmptyResultDataAccessException e) {
//key is not present, so no need to delete it
return null;
}
//delete row and return old value
int updated = this.jdbcTemplate.update(this.removeValueQuery, key, this.region);
if (updated != 0) {
return oldValue;
}
return null;
}
}