下面是一些格式化参数说明(摘自Core Java 2 Volume I - Fundamentals, Seventh Edition)
Table 3-5. Conversions for printf
| Conversion Character | Type | Example |
| d | Decimal integer | 159 |
| x | Hexadecimal integer | 9f |
| o | Octal integer | 237 |
| f | Fixed-point floating-point | 15.9 |
| e | Exponential floating-point | 1.59E+01 |
| g | General floating-point (the shorter of e and f) | |
| a | Hexadecimal floating point | 0x1.fccdp3 |
| s | String | Hello |
| c | Character | H |
| b | Boolean | TRUE |
| h | Hash code | 42628b2 |
| tx | Date and time | See Table 3-7 |
| % | The percent symbol | % |
| n | The platform-dependent line separator |
Table 3-7. Date and Time Conversion Characters
| Conversion Character | Type | Example |
| C | Complete date and time | Mon Feb 09 18:05:19 PST 2004 |
| F | ISO 8601 date | 2004-02-09 |
| D | U.S. formatted date (month/day/year) | 02/09/2004 |
| T | 24-hour time | 18:05:19 |
| r | 12-hour time | 06:05:19 pm |
| R | 24-hour time, no seconds | 18:05 |
| Y | Four-digit year (with leading zeroes) | 2004 |
| y | Last two digits of the year (with leading zeroes) | 04 |
| C | First two digits of the year (with leading zeroes) | 20 |
| B | Full month name | February |
| b or h | Abbreviated month name | Feb |
| m | Two-digit month (with leading zeroes) | 02 |
| d | Two-digit day (with leading zeroes) | 09 |
| e | Two-digit day (without leading zeroes) | 9 |
| A | Full weekday name | Monday |
| a | Abbreviated weekday name | Mon |
| j | Three-digit day of year (with leading zeroes), between 001 and 366 | 069 |
| H | Two-digit hour (with leading zeroes), between 00 and 23 | 18 |
| k | Two-digit hour (without leading zeroes), between 0 and 23 | 18 |
| I | Two-digit hour (with leading zeroes), between 01 and 12 | 06 |
| l | Two-digit hour (without leading zeroes), between 1 and 12 | 6 |
| M | Two-digit minutes (with leading zeroes) | 05 |
| S | Two-digit seconds (with leading zeroes) | 19 |
| L | Three-digit milliseconds (with leading zeroes) | 047 |
| N | Nine-digit nanoseconds (with leading zeroes) | 047000000 |
| P | Uppercase morning or afternoon marker | PM |
| p | Lowercase morning or afternoon marker | pm |
| z | RFC 822 numeric offset from GMT | -0800 |
| Z | Time zone | PST |
| s | Seconds since 1970-01-01 00:00:00 GMT | 1078884319 |
| E | Milliseconds since 1970-01-01 00:00:00 GMT | 1078884319047 |
Table 3-6. Flags for printf
| Flag | Purpose | Example |
| + | Prints sign for positive and negative numbers | +3333.33 |
| space | Adds a space before positive numbers | | 3333.33| |
| 0 | Adds leading zeroes | 003333.33 |
| - | Left-justifies field | |3333.33 | |
| ( | Encloses negative number in parentheses | (3333.33) |
| , | Adds group separators | 3,333.33 |
| # (for f format) | Always includes a decimal point | 3,333. |
| # (for x or o format) | Adds 0x or 0 prefix | 0xcafe |
| ^ | Converts to upper case | 0XCAFE |
| $ | Specifies the index of the argument to be formatted; for example, %1$d %1$x prints the first argument in decimal and hexadecimal | 159 9F |
| < | Formats the same value as the previous specification; for example, %d % |
这里是一些简单的介绍，更详细的说明请参考：
Core Java 2 Volume I - Fundamentals, Seventh Edition
Core Java 2 Volume II - Advanced Features, Seventh Edition
里面都有一些很精彩的描述，中文名称就是《Java核心技术》。只有第七版才有J2SE5.0的介绍，但是第七版好像还没有中文版。本文还参考了Professional Java JDK - 5th Edition.
