fun.langel.cql.datasource.DataSourceHolder Maven / Gradle / Ivy

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package fun.langel.cql.datasource;

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

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @author [email protected](GuHan)
 * @since 2022/8/9 20:35
 **/
public class DataSourceHolder {

    private static final Logger LOG = LoggerFactory.getLogger(DataSourceHolder.class);
    private DataSource dataSource;

    private final String name;

    private final Class klass;

    private final int priority;

    private DataSourceHolder(final Class klass,
                             final String name,
                             final int priority) {
        this.klass = klass;
        this.name = name;
        this.priority = priority;
    }

    public int priority() {
        return this.priority;
    }

    public DataSource getDataSource() {

        if (this.dataSource == null) {
            synchronized (this) {
                if (this.dataSource == null) {
                    lazy();
                }
            }
        }
        return this.dataSource;
    }

    private DataSource lazy() {
        this.dataSource = create();
        return this.dataSource;
    }

    private DataSource create() {
        Class kls = this.klass;
        try {
            return (DataSource) kls.newInstance();
        } catch (Exception ex) {
            LOG.error(ex.getMessage(), ex);
            return null;
        }
    }

    public String name() {
        return this.name;
    }

    public Class klass() {
        return this.klass;
    }

    public static Builder builder() {
        return new Builder();
    }

    public static class Builder {

        private Class klass;

        private String name;

        private int priority;

        private Builder() {
        }

        public Builder setKlass(final Class klass) {
            this.klass = klass;
            return this;
        }

        public Builder setName(final String name) {
            this.name = name;
            return this;
        }

        public Builder setPriority(final int priority) {
            this.priority = priority;
            return this;
        }

        public DataSourceHolder build() {
            return new DataSourceHolder(this.klass, this.name, this.priority);
        }
    }
}