package com.fasterxml.jackson.core; import java.io.IOException; /** * Interface for objects that implement pretty printer functionality, such * as indentation. * Pretty printers are used to add white space in output JSON content, * to make results more human readable. Usually this means things like adding * linefeeds and indentation. *<p> * Note: since Jackson 2.1, stateful implementations MUST implement * {@link com.fasterxml.jackson.core.util.Instantiatable} interface, * to allow for constructing per-generation instances and avoid * state corruption (see [JACKSON-851] for details). * Stateless implementations need not do this; but those are less common. */ public interface PrettyPrinter { /* /********************************************************** /* First methods that act both as events, and expect /* output for correct functioning (i.e something gets /* output even when not pretty-printing) /********************************************************** */ // // // Root-level handling: /** * Method called after a root-level value has been completely * output, and before another value is to be output. *<p> * Default * handling (without pretty-printing) will output a space, to * allow values to be parsed correctly. Pretty-printer is * to output some other suitable and nice-looking separator * (tab(s), space(s), linefeed(s) or any combination thereof). */ void writeRootValueSeparator(JsonGenerator jg) throws IOException, JsonGenerationException; // // Object handling /** * Method called when an Object value is to be output, before * any fields are output. *<p> * Default handling (without pretty-printing) will output * the opening curly bracket. * Pretty-printer is * to output a curly bracket as well, but can surround that * with other (white-space) decoration. */ void writeStartObject(JsonGenerator jg) throws IOException, JsonGenerationException; /** * Method called after an Object value has been completely output * (minus closing curly bracket). *<p> * Default handling (without pretty-printing) will output * the closing curly bracket. * Pretty-printer is * to output a curly bracket as well, but can surround that * with other (white-space) decoration. * * @param nrOfEntries Number of direct members of the array that * have been output */ void writeEndObject(JsonGenerator jg, int nrOfEntries) throws IOException, JsonGenerationException; /** * Method called after an object entry (field:value) has been completely * output, and before another value is to be output. *<p> * Default handling (without pretty-printing) will output a single * comma to separate the two. Pretty-printer is * to output a comma as well, but can surround that with other * (white-space) decoration. */ void writeObjectEntrySeparator(JsonGenerator jg) throws IOException, JsonGenerationException; /** * Method called after an object field has been output, but * before the value is output. *<p> * Default handling (without pretty-printing) will output a single * colon to separate the two. Pretty-printer is * to output a colon as well, but can surround that with other * (white-space) decoration. */ void writeObjectFieldValueSeparator(JsonGenerator jg) throws IOException, JsonGenerationException; // // // Array handling /** * Method called when an Array value is to be output, before * any member/child values are output. *<p> * Default handling (without pretty-printing) will output * the opening bracket. * Pretty-printer is * to output a bracket as well, but can surround that * with other (white-space) decoration. */ void writeStartArray(JsonGenerator jg) throws IOException, JsonGenerationException; /** * Method called after an Array value has been completely output * (minus closing bracket). *<p> * Default handling (without pretty-printing) will output * the closing bracket. * Pretty-printer is * to output a bracket as well, but can surround that * with other (white-space) decoration. * * @param nrOfValues Number of direct members of the array that * have been output */ void writeEndArray(JsonGenerator jg, int nrOfValues) throws IOException, JsonGenerationException; /** * Method called after an array value has been completely * output, and before another value is to be output. *<p> * Default handling (without pretty-printing) will output a single * comma to separate the two. Pretty-printer is * to output a comma as well, but can surround that with other * (white-space) decoration. */ void writeArrayValueSeparator(JsonGenerator jg) throws IOException, JsonGenerationException; /* /********************************************************** /* Then events that by default do not produce any output /* but that are often overridden to add white space /* in pretty-printing mode /********************************************************** */ /** * Method called after array start marker has been output, * and right before the first value is to be output. * It is <b>not</b> called for arrays with no values. *<p> * Default handling does not output anything, but pretty-printer * is free to add any white space decoration. */ void beforeArrayValues(JsonGenerator jg) throws IOException, JsonGenerationException; /** * Method called after object start marker has been output, * and right before the field name of the first entry is * to be output. * It is <b>not</b> called for objects without entries. *<p> * Default handling does not output anything, but pretty-printer * is free to add any white space decoration. */ void beforeObjectEntries(JsonGenerator jg) throws IOException, JsonGenerationException; }