http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Bf1GHnXv
} ;TmwIZ
for(int i=0;i<nEndPos.length-1;i++) s]L`&fY]O
{ Cd7jG
nEndPos = nStartPos[i+1]; Se"\PxBR
} K_]LK
nEndPos[nEndPos.length-1] = nFileLength; t@}<&{zk
} A6lf-8ncx
} feNr!/
sN-5vYfC*
TQ=\l*R(A
//启动子线程 T]Tz<w W(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; l3-KswU
for(int i=0;i<nStartPos.length;i++) Fj1/B0acS
{ %|SbZ)gcQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,>{4*PM(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "^_p>C)T
nStartPos,nEndPos,i); *sAoYx
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <6dD{{J]>p
fileSplitterFetch.start(); jJ55Az?t:
} Mk@_uPm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bRNE:))r_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ><\mt
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'G-VhvMv
nEndPos = " + nFileLength); T:;e73
// fileSplitterFetch[nPos.length-1].start(); J'@I!Jc
<+_OgF1G
9!2KpuWji
//等待子线程结束 r}f-.Fo
//int count = 0; 7dPA>5"XD
//是否结束while循环 ,:>>04O
boolean breakWhile = false; g'pE z
S_?}H
>:OOuf#
while(!bStop) qf)]!wU9
{ 9!bD|-6y
write_nPos(); xBB:b\
Utility.sleep(500); akd~Z
breakWhile = true; 2$\1v*:
~JC``&6E=}
yaR|d3ef?4
for(int i=0;i<nStartPos.length;i++) ^o,@9GTs
{ 1O(fI|gcO
if(!fileSplitterFetch.bDownOver) Aba6/
{ YXV![gw0
breakWhile = false; E8%O+x}
break; NNe'5q9
} z W+wtYV4
} k9}im
if(breakWhile) }E?s*iP
break; 2jx""{
/^4)V8D_S
xFg=Tyq:
//count++; W!IK>IW"
//if(count>4) AqN(htGvx
// siteStop(); PCw.NJd$
} w?Q@"^IL
'7Te{^<FQ$
_9L2JN$R6
System.err.println("文件下载结束！"); :&_@U$
} oWXvkDN
catch(Exception e){e.printStackTrace ();} &2QN^)q
} rycscE4,
2a? d:21 B
ge[\%
//获得文件长度 D;Az>]>q
public long getFileSize() @Ki`g(],P
{ >St
int nFileLength = -1; h!d#=.R
try{ !*CL>}-,
URL url = new URL(siteInfoBean.getSSiteURL()); 0CTI=<;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +?mZ_sf8w
httpConnection.setRequestProperty("User-Agent","NetFox"); ^~(bm$4r
X^aujK^@
yGS._;#R
int responseCode=httpConnection.getResponseCode(); T( ;BEyc?
if(responseCode>=400) bZ3CJ f&mE
{ 1 #EmZ{*
processErrorCode(responseCode); <Xl G:nmY
return -2; //-2 represent access is error 4=q\CK2^A
} (/qY*?
\;P Bx &
-Ep-v4}
String sHeader; YdeSJ(:
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WBC'~h<@
for(int i=1;;i++) {{2ZWK 6|
{ U6M4}q(N]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); eQC`e#%
//Utility.log(in.readLine()); _k ~bH\(
sHeader=httpConnection.getHeaderFieldKey(i); Q%t8cJL
if(sHeader!=null) ;| \Ojuf
{ F}sfk}rp
if(sHeader.equals("Content-Length")) [0J0<JnK
{ R \`,Q'3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {BKI8vy
break; J+z0,N[
} qPzgGbmD9
} > ]6Eb`v
else V2.MZ9
break; u_:" u
} 7&T1RB'>
} D, 3x:nK
catch(IOException e){e.printStackTrace ();} Y9PG
catch(Exception e){e.printStackTrace ();} (_-zm)F7
@Vb-BC,
:T'"%_d5
Utility.log(nFileLength); Rl6E
lW>bXC
V$:v~*Y9
return nFileLength; (a)d7y.oo
} kyY tL_SD
;PLby]=O
'9^x"U9c
//保存下载信息（文件指针位置） e%UFY-2
private void write_nPos() kA#>Xu/
{ vk[Km[(U'
try{ @$~%C) %u
output = new DataOutputStream(new FileOutputStream(tmpFile)); #]:nQ(
output.writeInt(nStartPos.length); }dB01Jl '
for(int i=0;i<nStartPos.length;i++) S{ *RF)
{ q$H'u[KQ06
// output.writeLong(nPos); wt)tLMEv
output.writeLong(fileSplitterFetch.nStartPos); tWc!!Hf2j
output.writeLong(fileSplitterFetch.nEndPos); nq_sbli
} K3\U'bRO
output.close(); nwV\[E
} O<o_MZN
catch(IOException e){e.printStackTrace ();} ^Z}INUv]7
catch(Exception e){e.printStackTrace ();} V1"+4&R^T_
} seq S*^7
nk6xavQji
Kb4u)~S:
//读取保存的下载信息（文件指针位置） NCl={O9<j
private void read_nPos() wAy;ZNu
{ QF\NHV
try{ gv<9XYByt
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =\_MJ?A$
int nCount = input.readInt(); h^[K= J
nStartPos = new long[nCount]; [g<6i.<I
nEndPos = new long[nCount]; \Dr@n^hk@[
for(int i=0;i<nStartPos.length;i++) oYqlN6n,=6
{ #x"pG
nStartPos = input.readLong(); E#_}y}7JY
nEndPos = input.readLong(); tJg
} qY0GeE>N
input.close(); t;E-9`N
} BIX%Bu0'f
catch(IOException e){e.printStackTrace ();} qW7S<ouh
catch(Exception e){e.printStackTrace ();} -bKli<C
} WXXLD:gxI
(MbI8B>
{]|};E[}m
private void processErrorCode(int nErrorCode) tQUp1i{j\
{ G~YV6??
System.err.println("Error Code : " + nErrorCode); HH[?LKd<
} yjN|PqtSV
>mh:OJH45
PsLuyGR.<
//停止文件下载 =;c? 6{<1
public void siteStop() J}<k`af
{ .cle^P
bStop = true; 5H?`a7q N
for(int i=0;i<nStartPos.length;i++) Q0nSOTQ
fileSplitterFetch.splitterStop(); gxL5%:@
HiVF<tN
K3 "co1]u
} n_?<q{GW
} Po=)jkW
//负责部分文件的抓取 #CVD:p
**FileSplitterFetch.java uKtrG,/ p
*/ iVnrv`k,
package NetFox; 6P+8{?V&
,uuQj]Dac+
PZH]9[H
import java.io.*; [)9bR1wh
import java.net.*; 1kTJMtZG~
e 0!a &w
tQ] R@i
public class FileSplitterFetch extends Thread { N6yqA)z?;
(~/D*<A
{P-KU RQ
String sURL; //File URL blxH`O!
long nStartPos; //File Snippet Start Position -Z]?v3 9
long nEndPos; //File Snippet End Position sa*]q~a
int nThreadID; //Thread's ID /koNcpJ
boolean bDownOver = false; //Downing is over !L-.bve!
boolean bStop = false; //Stop identical (q3(bH~T)
FileAccessI fileAccessI = null; //File Access interface O,:ent|
o_os;
&|Z:8]'P
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T4qbyui{
{ _0^<)OSY
this.sURL = sURL; 6}{2W<
this.nStartPos = nStart; Jp_{PR:&
this.nEndPos = nEnd; F]SexP4:A
nThreadID = id; E}\^GNT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MT;<\T
} Q_LPLmM
IN`05Q
fm:/}7s
public void run() ':F{st>&H
{ *1}9`$
while(nStartPos < nEndPos && !bStop) "D8xHHb
{ uXu'I
q^Oq:l$s
N$?mula
try{ /gXli)
URL url = new URL(sURL); .|KxQn}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -twIF49
httpConnection.setRequestProperty("User-Agent","NetFox"); GVn7#0x
String sProperty = "bytes="+nStartPos+"-"; ,GZ(>|
httpConnection.setRequestProperty("RANGE",sProperty); yq\)8Fe
Utility.log(sProperty); %=\h=\wt
L{'qZ#N[
p;BdzV>
InputStream input = httpConnection.getInputStream(); 4$d|}ajH
//logResponseHead(httpConnection); d/Fjs0pt
`;5UlkVZ5
az0( 54M
byte[] b = new byte[1024]; Og"50-
int nRead; ObMsncn
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )v8;\1`s:
{ k/!Vv#8
nStartPos += fileAccessI.write(b,0,nRead); w0tlF:Eg
//if(nThreadID == 1) c3i|q@ k
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e+4p__TmZ
} ^/mQo`[G
LQNu]2
m7^a4
Utility.log("Thread " + nThreadID + " is over!"); ?i)-K?4Sb
bDownOver = true; mmr>"`5.
//nPos = fileAccessI.write (b,0,nRead); ,LWM}L
} 3 +BPqhzf
catch(Exception e){e.printStackTrace ();} W&BwBp]K
} %w6> 3#e
} X#1So.}c
_(J- MCY\
oQWS$\Rr.
//打印回应的头信息 G-bG}9vc]
public void logResponseHead(HttpURLConnection con) iN+p>3w^l
{ tNmH*"wR<
for(int i=1;;i++) B;hc|v{(
{ 0%`\8
String header=con.getHeaderFieldKey(i); f9&D0x?
if(header!=null) 76$19
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +J_A*B
Utility.log(header+" : "+con.getHeaderField(header)); (. 1<.PZp)
else .l !:|Fd
break; u%VO'}Gz
} f![x7D$
} .Eh~$wm
zUIh8cAoE
ZUAWSJ,s
public void splitterStop() sB-c'`,w`
{ 0ydAdgD
bStop = true; eey <:n/Z
} yTkYPx
bN<c5
d7$H})[^
} T*-*U/
@\u)k
%jKR\f G
/* 3,3{wGvHHW
**FileAccess.java g%1!YvS3v
*//文件访问(定位，写) roj/GZAy"
package NetFox; <MA!?7Z|
import java.io.*; (RWZ[-;)
Y@M=6G
REQ2pfk0
public class FileAccessI implements Serializable{ Ml+.\'r
h7[VXE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :v1'(A1t
RandomAccessFile oSavedFile; +=$]fjE?
long nPos; V:QfI
kh^AH6{2
qSkt }F%'
public FileAccessI() throws IOException OA4NXl'
{ RvYew!n
this("",0); 0wAZ9AxA{
} ruB&&C6)v
sZ]O&Za~
=qCVy:RL4
public FileAccessI(String sName,long nPos) throws IOException (U/6~r'.L
{ ;9=9D{-4+
oSavedFile = new RandomAccessFile(sName,"rw"); Crm](Z?
this.nPos = nPos; QRgWzaI
oSavedFile.seek(nPos); uC 5mxZ
} s-k~_C>Fw
6jPaS!E
(gl CTF9v
public synchronized int write(byte[] b,int nStart,int nLen) C.%iQx`
{ q+WOnTS
int n = -1; tojJQ6;J
try{ Z9~~vf#
oSavedFile.write(b,nStart,nLen); E I)Pfx"0
n = nLen; 3`SLMPI
} *~prI1e(
catch(IOException e) hk}M'
{ K ,f1c}
e.printStackTrace (); #s(B,`?N
} <W|{zAyv
(.<Gde#
b0riiF
return n; Xb)XV$0
} $M$oNOT}Y
T7Lk4cU
9n|H%AC
} xqmJPbA
%}+j4n
Y\dK-M{$
/* \>23_d0
**SiteInfoBean.java ^p|@{4f]
*/ P,xayy
package NetFox; h"#^0$f
0Q]x[;!k
- Kj$A@~x
public class SiteInfoBean { ,UH`l./3DX
o=w&&B
PKwHq<vAsB
private String sSiteURL; //Site's URL PX\}lTJ
private String sFilePath; //Saved File's Path e9k}n\t3
private String sFileName; //Saved File's Name 2ZNTg@o
private int nSplitter; //Count of Splited Downloading File 0(@8
MfCu\[qOz
/<zBcpVNV
public SiteInfoBean() n KDX=73
{//nSplitter的缺省值为5 +3]@0VM26;
//default value of nSplitter is 5 m-*du(
this("","","",5); Ocx=)WKdW
} 9);a0}*5
_S2QY7/
p?0 a"5Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Lo7R^>
{ /LPSI^l!m
sSiteURL= sURL; sBZKf8@/
sFilePath = sPath; g9GE0DbT`
sFileName = sName; ~Jmn?9 3
this.nSplitter = nSpiltter; UZmzk
UKMrR9[x*
&R\ .^3
} ]Ol@^$8}
c}g^wLa
q,0o:nI
public String getSSiteURL() ^[\F uSL
{ -;Cl0O%
return sSiteURL; e|"`W`"-
} Y]B2-wt-
l: 1Zq_?v;
WASs'Gx
public void setSSiteURL(String value) M6pGf_qt
{ {hZ_f3o
sSiteURL = value; M2my>
} FyZw='D
s-o0N{b?#'
}"Hf/{E$_"
public String getSFilePath() pYceMZ$
{ bYgrKz@uK
return sFilePath; 'JKFEUzM
} \qNj?;B
5a5I+* c
2+sNt6B2
public void setSFilePath(String value) &0Wv+2l@
{ &"K74
sFilePath = value; Z3~$"V*ZB{
} -'5:Cq
f{^C+t{r
42ttmN1F
public String getSFileName() Mf/zSQk+
{ 0&2TeqsLh)
return sFileName; MFiX8zwhx+
} |v[{k>7f
%89f<F\V
;}=v|Dr&I.
public void setSFileName(String value) A4Q8^^byY
{ **fJAANc
sFileName = value; $-jj%x\}
} <M7@JgC &
EAj2uV
^qS[2Dy
public int getNSplitter() T$0//7$')
{ ,]y)Dy
return nSplitter; 0rsdDME[
} FL/@e$AK
"9&6bBa
zRL[.O9
public void setNSplitter(int nCount) ! Hdg $,
{ H2E!A2\m
nSplitter = nCount; K$R1x1lc2
} &]16Hb~
} }yK_2zak5i
A^bg*t,
daGGgSbh
/* C8-4 m68"
**Utility.java 8QXxRD;0:
*/ UfOF's_'<
package NetFox; B9>3xxp(by
z )a8 ^]`
]y2(ZTNTs
public class Utility { R1 hb-
7t0\}e
R1{"
public Utility() sn}U4=u
{ -KCm#!
bo0m/hVU
j42U|CuK
} ) e;)9~
z,X ^;
//线程睡眠 PfF7*}P
public static void sleep(int nSecond) UyEyk$6SU
{ N6Vn/7I5%
try{ 6AUXYbK,
Thread.sleep(nSecond); XB50>??NE
} iVFHr<zk
catch(Exception e) o'D{ql
{ ,*bI0mFZ
e.printStackTrace (); ^7.864
} Tm.(gK
} .B6$U>>NS^
_^0yE_ili
//日志 k$i76r
public static void log(String sMsg) |9?67-
{ M$FQoRwH
System.err.println(sMsg); OzA"i y
} U~s&}M\n
V`l.F"<L
v,KH2 (N
public static void log(int sMsg) M9fAv
{ rPv+eM">
System.err.println(sMsg); #hH"g
} D""d-oI[
} U*(m'Ea
u f.Zg;Vc
%$~?DDNM
/* 1YTnOiYS1
**TestMethod.java ]O,!B''8k
*/ y4/>3tz;
package NetFox; 5Q?7 xTQ
)^|zuYzN
]mn(lK
public class TestMethod { 0"ZB|^c=
kgEGL]G>
G!ty@ Fx
public TestMethod() ",B92[}Ar
{ ///xx/weblogic60b2_win.exe xzyV|(
try{ 5dXC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i jg'X#E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $83TA><a
SiteFileFetch fileFetch = new SiteFileFetch(bean); ']Nw{}eS`
fileFetch.start(); v< xe(dC
} j;=+5PY
catch(Exception e){e.printStackTrace ();} MV-fDqA(
3G~ T_J&
B;SYO>.W
} PxM]3Aoa
Gm}ecW
LrX7WI
public static void main(String[] args) %i]q} M
{ JcvWE $
new TestMethod(); %t([
} 0vqXLFf
} pfe9n[
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