Java引擎调用实例

最近做项目时遇到项目间相互调用的功能，开始打算用webservice来解决，但是考虑到性能问题已经时间等待问题，最终还是决定通过Java公式调用方式解决，一下为部分调用代码

package seentao.imp.formula;

import static test.imp.formula.FormulaExecTypeEnum.JAVA_METHOD;
import static test.imp.formula.FormulaExecTypeEnum.JS_SCRIPT;
import static test.imp.formula.FormulaExecTypeEnum.SQL_CAUSE;

import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

import org.mozilla.javascript.Context;
import org.mozilla.javascript.ScriptableObject;

public class FormulaInvoker {
	
	private Context cx;
	private ScriptableObject scope;
	private SimpleDateFormat dateFmt;
	private boolean reInit = true;
	private FormulaVO[] fmlVOs;
	
	private static final String JAVA_METHOD_NAME_KEY = "invokeJavaMethod"; 
	private static final String SQL_CAUSE_NAME_KEY = "invokeSqlCause"; 
	private static final String JAVA_SCRIPT_NAME_KEY = "invokeJavaScript"; 
	
	public void setFmlVOs(FormulaVO[] fmlVOs) {
		this.fmlVOs = fmlVOs;
	}
	
	public void init() {
		if (reInit) {
			cx = Context.enter();
			scope = cx.initStandardObjects();
			dateFmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
			for (FormulaVO vo : fmlVOs) {
				String source = null;
				if (JAVA_METHOD.equals(vo.getExec_type())) {
					source = createScriptSource(vo.getFunc_name(), JAVA_METHOD_NAME_KEY, vo.getFml_code());
				} else if (SQL_CAUSE.equals(vo.getExec_type())) {
					source = createScriptSource(vo.getFunc_name(), SQL_CAUSE_NAME_KEY, vo.getFml_code());
				} else if (JS_SCRIPT.equals(vo.getExec_type())) {
					source = createScriptSource(vo.getFunc_name(), JAVA_SCRIPT_NAME_KEY, vo.getFml_code());
				}
				cx.evaluateString(scope, source, "", 0, null);
			}
			reInit = false;
		}
	}
	
	public void reset() {
		reInit = true;
	}
	
	public Object invoke(FormulaVO fmlVO, Map<String, Object> params) {
		if (params == null) {
			params = new HashMap<String, Object>();
		}
		
		// 注入参数
		for (Entry<String, Object> entry : params.entrySet()) {
			scope.put(entry.getKey(), scope, entry.getValue());
		}

		// 执行脚本函数
		String funcExp = String.format("'' + %s", fmlVO.getFunc_name());
//可以直接得到调用项目的结果
		Object result = cx.evaluateString(scope, funcExp, "", 0, null);

		// 清除参数
		for (Entry<String, Object> entry : params.entrySet()) {
			scope.delete(entry.getKey());
		}

		// 处理结果
		String returnType = fmlVO.getReturn_type();
		try {
			if (FormulaReturnType.BOOLEAN.equals(returnType)) {
				return "true".equals(result);
			} else if (FormulaReturnType.BYTE.equals(returnType)) {
				return Byte.parseByte(result.toString());
			} else if (FormulaReturnType.SHORT.equals(returnType)) {
				return Short.parseShort(result.toString());
			} else if (FormulaReturnType.INTEGER.equals(returnType)) {
				return Integer.parseInt(result.toString());
			} else if (FormulaReturnType.LONG.equals(returnType)) {
				return Long.parseLong(result.toString());
			} else if (FormulaReturnType.FLOAT.equals(returnType)) {
				return Float.parseFloat(result.toString());
			} else if (FormulaReturnType.DOUBLE.equals(returnType)) {
				return Double.parseDouble(result.toString());
			} else if (FormulaReturnType.STRING.equals(returnType)) {
				return result.toString();
			} else if (FormulaReturnType.DATE.equals(returnType)) {
				return dateFmt.parse((String) result);
			} else if (FormulaReturnType.ARRAY.equals(returnType)) {
				return result.toString();
			} else if (FormulaReturnType.TWO_DIM_ARRAY.equals(returnType)) {
				return result.toString();
			} else {
				return result;
			}
		} catch (Exception e) {
			e.printStackTrace();
			return e.getMessage();
		}
	}
	
	public void exit() {
		Context.exit();
	}
	
	private String createScriptSource(String funcName, String methodName, String code) {
		code = code.replaceAll("\"", "\\\\\"");
		if (JAVA_SCRIPT_NAME_KEY.equals(methodName)) {
			return createScriptSource(funcName, code);
		} else {
			if (SQL_CAUSE_NAME_KEY.equals(methodName)) {
				code = code.trim();
				if (code.indexOf("\\n") > 0) {
					code = code.replaceAll("\\n", "");
				}
			}
			String source = String.format("function %s {%n" +
					"\treturn Packages.seentao.imp.formula.FormulaProxy.%s(\"%s\", arguments);%n" +
			"}%n", funcName, methodName, code);
			return source;
		}
	}
	
	private String createScriptSource(String funcName, String code) {
		code = code.indexOf("return ")>=0 ? code : "return " + code;
		return String.format("function %s {try{%s;}catch(e){return e;}}%n", funcName, code);
	}
	
}

  关于Java引擎可参见：

http://blog.youkuaiyun.com/zhengyuanting/article/details/2973972