fess/src/main/java/org/codelibs/fess/api/BaseJsonApiManager.java

package org.codelibs.fess.api;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.util.Map;

import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang3.StringEscapeUtils;
import org.codelibs.core.CoreLibConstants;
import org.codelibs.core.lang.StringUtil;
import org.codelibs.fess.Constants;
import org.codelibs.fess.exception.InvalidAccessTokenException;
import org.lastaflute.web.util.LaRequestUtil;
import org.lastaflute.web.util.LaResponseUtil;

public abstract class BaseJsonApiManager extends BaseApiManager {

    protected void writeJsonResponse(final int status, final String body, final Throwable t) {
        if (t == null) {
            writeJsonResponse(status, body, (String) null);
            return;
        }

        if (t instanceof InvalidAccessTokenException) {
            final InvalidAccessTokenException e = (InvalidAccessTokenException) t;
            final HttpServletResponse response = LaResponseUtil.getResponse();
            response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
            response.setHeader("WWW-Authenticate", "Bearer error=\"" + e.getType() + "\"");
        }

        final StringBuilder sb = new StringBuilder();
        if (StringUtil.isBlank(t.getMessage())) {
            sb.append(t.getClass().getName());
        } else {
            sb.append(t.getMessage());
        }
        final StringWriter sw = new StringWriter();
        t.printStackTrace(new PrintWriter(sw));
        sb.append(" [ ").append(sw.toString()).append(" ]");
        try {
            sw.close();
        } catch (final IOException ignore) {}
        writeJsonResponse(status, body, sb.toString());
    }

    protected void writeJsonResponse(final int status, final String body, final String errMsg) {
        final String callback = LaRequestUtil.getRequest().getParameter("callback");
        final boolean isJsonp = StringUtil.isNotBlank(callback);

        final StringBuilder buf = new StringBuilder(1000);
        if (isJsonp) {
            buf.append(escapeCallbackName(callback));
            buf.append('(');
        }
        buf.append("{\"response\":");
        buf.append("{\"version\":");
        buf.append(Constants.WEB_API_VERSION);
        buf.append(',');
        buf.append("\"status\":");
        buf.append(status);
        if (status == 0) {
            if (StringUtil.isNotBlank(body)) {
                buf.append(',');
                buf.append(body);
            }
        } else {
            buf.append(',');
            buf.append("\"message\":");
            buf.append(escapeJson(errMsg));
        }
        buf.append('}');
        buf.append('}');
        if (isJsonp) {
            buf.append(')');
        }
        write(buf.toString(), "text/javascript+json", Constants.UTF_8);

    }

    protected String escapeCallbackName(final String callbackName) {
        return "/**/" + callbackName.replaceAll("[^0-9a-zA-Z_\\$\\.]", StringUtil.EMPTY);
    }

    protected String escapeJson(final Object obj) {
        if (obj == null) {
            return "null";
        }

        final StringBuilder buf = new StringBuilder(255);
        if (obj instanceof List<?>) {
            buf.append('[');
            boolean first = true;
            for (final Object child : (List<?>) obj) {
                if (first) {
                    first = false;
                } else {
                    buf.append(',');
                }
                buf.append(escapeJson(child));
            }
            buf.append(']');
        } else if (obj instanceof Map<?, ?>) {
            buf.append('{');
            boolean first = true;
            for (final Map.Entry<?, ?> entry : ((Map<?, ?>) obj).entrySet()) {
                if (first) {
                    first = false;
                } else {
                    buf.append(',');
                }
                buf.append(escapeJson(entry.getKey())).append(':').append(escapeJson(entry.getValue()));
            }
            buf.append('}');
        } else if (obj instanceof Number) {
            buf.append(obj);
        } else if (obj instanceof Date) {
            final SimpleDateFormat sdf = new SimpleDateFormat(CoreLibConstants.DATE_FORMAT_ISO_8601_EXTEND, Locale.ROOT);
            buf.append('\"').append(StringEscapeUtils.escapeJson(sdf.format(obj))).append('\"');
        } else {
            buf.append('\"').append(StringEscapeUtils.escapeJson(obj.toString())).append('\"');
        }
        return buf.toString();
    }

}