動的SQLでPreparedStatement+プレースホルダを使用する

SQLBuilder.java

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class SQLBuilder {

	private StringBuilder sql = new StringBuilder();
	private List<BindParameter> params = new ArrayList<>();

	public SQLBuilder() {
	}

	public SQLBuilder(String sql) {
		this.sql.append(sql);
	}
	
	public SQLBuilder(String sql, BindParameter... params) {
		this.sql.append(sql);
		this.params.addAll(Arrays.asList(params));
	}

	public SQLBuilder append(String sql) {
		this.sql.append("\n");
		this.sql.append(sql);
		return this;
	}

	public SQLBuilder append(BindParameter... params) {
		this.params.addAll(Arrays.asList(params));
		return this;
	}

	public SQLBuilder append(String sql, BindParameter... params) {
		this.sql.append("\n");
		this.sql.append(sql);
		this.params.addAll(Arrays.asList(params));
		return this;
	}

	public PreparedStatement prepare(Connection conn) throws SQLException {
		return conn.prepareStatement(sql.toString());
	}

	public PreparedStatement prepareAndSetParameters(Connection conn) throws SQLException {
		PreparedStatement pstmt = prepare(conn);
		int i = 1;
		for (BindParameter param : params) {
			pstmt.setObject(i++, param.bindObject, param.sqlType);
		}
		return pstmt;
	}

	public static BindParameter param(Object bindObject, int sqlType) {
		return new BindParameter(bindObject, sqlType);
	}

	public static class BindParameter {

		private int sqlType;
		private Object bindObject;

		public BindParameter(Object bindObject, int sqlType) {
			this.sqlType = sqlType;
			this.bindObject = bindObject;
		}
	}
}