import net.sf.jsqlparser.expression.SignedExpression; //导入依赖的package包/类
@Override
public void visit(SignedExpression value)
{
	Expression underlyingValue = value.getExpression();
	if (underlyingValue instanceof DoubleValue)
	{
		DoubleValue doubleValue = (DoubleValue) underlyingValue;
		doubleValue.setValue(value.getSign() == '-' ? -doubleValue.getValue() : doubleValue.getValue());
		visit(doubleValue);
	}
	else if (underlyingValue instanceof LongValue)
	{
		LongValue longValue = (LongValue) underlyingValue;
		longValue.setValue(value.getSign() == '-' ? -longValue.getValue() : longValue.getValue());
		visit(longValue);
	}
	else
	{
		super.visit(value);
	}
}
 

import net.sf.jsqlparser.expression.SignedExpression; //导入依赖的package包/类
private static Object resolveValue(Expression expression, boolean allowColumn) throws StatementExecutionException {
    if (expression instanceof JdbcParameter) {
        throw new StatementExecutionException("jdbcparameter expression not usable in this query");
    } else if (allowColumn && expression instanceof net.sf.jsqlparser.schema.Column) {
        // this is only for supporting back ticks in DDL
        return ((net.sf.jsqlparser.schema.Column) expression).getColumnName();
    } else if (expression instanceof StringValue) {
        return ((StringValue) expression).getValue();
    } else if (expression instanceof LongValue) {
        return ((LongValue) expression).getValue();
    } else if (expression instanceof TimestampValue) {
        return ((TimestampValue) expression).getValue();
    } else if (expression instanceof SignedExpression) {
        SignedExpression se = (SignedExpression) expression;
        switch (se.getSign()) {
            case '+': {
                return resolveValue(se.getExpression(), allowColumn);
            }
            case '-': {
                Object value = resolveValue(se.getExpression(), allowColumn);
                if (value == null) {
                    return null;
                }
                if (value instanceof Integer) {
                    return -1L * ((Integer) value);
                } else if (value instanceof Long) {
                    return -1L * ((Long) value);
                } else {
                    throw new StatementExecutionException("unsupported value type " + expression.getClass() + " with sign " + se.getSign() + " on value " + value + " of type " + value.getClass());
                }
            }
            default:
                throw new StatementExecutionException("unsupported value type " + expression.getClass() + " with sign " + se.getSign());
        }

    } else {
        throw new StatementExecutionException("unsupported value type " + expression.getClass());
    }
}
 

import net.sf.jsqlparser.expression.SignedExpression; //导入依赖的package包/类
@Override
public void visit(SignedExpression signedExpression) {
    buffer.append(signedExpression.getSign());
    signedExpression.getExpression().accept(this);
}
 

import net.sf.jsqlparser.expression.SignedExpression; //导入依赖的package包/类
@Override
public void visit(SignedExpression signedExpression) {
    signedExpression.getExpression().accept(this);
}
 

import net.sf.jsqlparser.expression.SignedExpression; //导入依赖的package包/类
@Override
public void visit(SignedExpression signedExpression) {
    // TODO Auto-generated method stub
    
}
 

import net.sf.jsqlparser.expression.SignedExpression; //导入依赖的package包/类
@Override
public void visit(SignedExpression se) {
    se.getExpression().accept(this);
}
 

import net.sf.jsqlparser.expression.SignedExpression; //导入依赖的package包/类
@Override
public void visit(SignedExpression signedExpression) {
    context.setNegative('-' == signedExpression.getSign());
    signedExpression.getExpression().accept(this);
    context.setNegative(false);
}
 

import net.sf.jsqlparser.expression.SignedExpression; //导入依赖的package包/类
public void visit(SignedExpression signedExpression) {
}
 

import net.sf.jsqlparser.expression.SignedExpression; //导入依赖的package包/类
@Override
public void visit(SignedExpression arg0) {
	isSimple = false;
	
}
 

import net.sf.jsqlparser.expression.SignedExpression; //导入依赖的package包/类
@Override
public void visit(SignedExpression signed)
{
   throw new UnsupportedSqlExpressionException("SIGNED"); //$NON-NLS-1$
}
 

import net.sf.jsqlparser.expression.SignedExpression; //导入依赖的package包/类
@Override
public void visit(SignedExpression signed)
{
   throw new IllegalOperationException("Illegal SQL ON expression: " + signed); //$NON-NLS-1$
}
 

import net.sf.jsqlparser.expression.SignedExpression; //导入依赖的package包/类
@Override
public void visit(SignedExpression se) {
}
 

import net.sf.jsqlparser.expression.SignedExpression; //导入依赖的package包/类
@Override
public void visit(SignedExpression signedExpression) {

}