mvel如何解析sql,代码示例

MVEL 可以通过使用 SQLTransformer 类来解析 SQL 语句，示例代码如下：

import org.mvel2.MVEL;
import org.mvel2.integration.impl.MapVariableResolverFactory;
import org.mvel2.templates.res.CompiledExpression;
import org.mvel2.templates.res.Node;
import org.mvel2.templates.res.TextNode;
import org.mvel2.transformer.Transformer;
import org.mvel2.transformer.TransformerFactory;
import org.mvel2.util.ParseTools;

import java.util.HashMap;
import java.util.Map;

public class MvelSqlDemo {
    public static void main(String[] args) {
        String sql = "SELECT * FROM users WHERE name = :name AND age > :age";
        Map<String, Object> params = new HashMap<>();
        params.put("name", "John");
        params.put("age", 18);

        Transformer transformer = TransformerFactory.getTransformer(Transformer.SQL);
        Node node = ParseTools.subCompileExpression(sql);
        CompiledExpression compiledExpression = new CompiledExpression(node);

        MapVariableResolverFactory factory = new MapVariableResolverFactory(params);
        transformer.transform(compiledExpression, factory);

        String result = ((TextNode) node).getText();
        System.out.println(result);
    }
}

以上代码演示了如何使用 MVEL 解析 SQL 语句，并将参数替换为实际的值。