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)); dUSuhT
} 5L#M7E
for(int i=0;i<nEndPos.length-1;i++) x#j_}L!V;
{ O v6=|]cW
nEndPos = nStartPos[i+1]; Big-)7?
} J?$uNlI
nEndPos[nEndPos.length-1] = nFileLength; 42LV>X#i
} 6d8
} SUhP e+
,Z"sh*
/VkJ+%}+j
//启动子线程 s:P-F0q!&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o*'3N/D~
for(int i=0;i<nStartPos.length;i++) WU_Q 7%+QS
{ 8+F2 !IM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v8N1fuP}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $hh=-#J8
nStartPos,nEndPos,i); -+/|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BJ/%{ C`g
fileSplitterFetch.start(); cG6+'=]3<
} \v Go5`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4+:u2&I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v)EJ|2`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5GP'cE
nEndPos = " + nFileLength); pUx@QyrI
// fileSplitterFetch[nPos.length-1].start(); AWcPOU
#*@Yil=1
'"a8<7
//等待子线程结束 tvILLR
//int count = 0; dtm@G|Ij
//是否结束while循环 0nAS4Az
boolean breakWhile = false; `mVH94{+I
[$X(i|6
NunT2JP.
while(!bStop) uc8>B&B%
{ HtlXbzN%)
write_nPos(); (aLnbJeJ
Utility.sleep(500); akoILX~u
breakWhile = true; 59u7q(
c\opPhJ!0
4 @h6|=
for(int i=0;i<nStartPos.length;i++) $MHc4FE[
{ ww*F}}(
if(!fileSplitterFetch.bDownOver) Emo]I[<&q
{ UPsh Y
breakWhile = false; :T2K\@
break; \)hmg
} e2v,#3Q\
} O^GTPYW
if(breakWhile) gnt[l0m
break; 7 m%|TwJN
@VFg XN
+dRTHz
//count++; TkykI
//if(count>4) pQD8#y)`C
// siteStop(); WD]dt!V%
} #'T@mA
~QXNOtVsN
l8Ox]%F
System.err.println("文件下载结束！"); iC">F.9#
} 6|9fcIh]B
catch(Exception e){e.printStackTrace ();} dc*#?G6^
} UNJ|J$T]
aqlYB7
tW +I?
//获得文件长度 .u)YZN0\
public long getFileSize() 5UqCRz<,R
{ Z|.. hZG
int nFileLength = -1; y g7z?AZ
try{ =y ff.3mW\
URL url = new URL(siteInfoBean.getSSiteURL()); 4CqZvdC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <K~#@.^`
httpConnection.setRequestProperty("User-Agent","NetFox"); |<S9nZg%p
(fl2?d5+C
rmhB!Lo
int responseCode=httpConnection.getResponseCode(); ;X>KP,/r$
if(responseCode>=400) /D~:Ufw
{ Vs(;al'
processErrorCode(responseCode); yl*S|= 8;k
return -2; //-2 represent access is error U i;o/Z3
} 6Dch+*4*@
h&XyMm9C
t}K?.To$
String sHeader; =+u$ZZ0+]o
"dt3peH
F!U+IztZ
for(int i=1;;i++) /lUb9&yV
{ ,}[,]-nVx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^I^k4iw4
//Utility.log(in.readLine()); !#3R<bW`R8
sHeader=httpConnection.getHeaderFieldKey(i); *+iWB_
if(sHeader!=null) [@(zGb8
{ |h;MA,qva
if(sHeader.equals("Content-Length")) 7G xNI
{ E+_}8J .
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "8N]1q:$4
break; -?ip?[Z
} 5p750`n
} dW91nTQ:
else [KJm&\evp
break; V9+7A
} >q}EZC
} I6UZ_H'E
catch(IOException e){e.printStackTrace ();} e3[N#ryt
catch(Exception e){e.printStackTrace ();} 'tOo0Zgc
Pai{?<zGi
b"J(u|Du`
Utility.log(nFileLength); FQ[::*-
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:f`1
return nFileLength; *l|CrUa
} BPW:W }
Ts^IA67&<
H|Eu,eq-E
//保存下载信息（文件指针位置） ,5nrovv
private void write_nPos() \aG>(Mr
{ 1=s%.0
try{ he/FtkU
output = new DataOutputStream(new FileOutputStream(tmpFile)); Eh JYdO[e
output.writeInt(nStartPos.length); YoXXelO&
for(int i=0;i<nStartPos.length;i++) 0 {w?u%'
{ t4nAy)I)P
// output.writeLong(nPos); %_5B"on
output.writeLong(fileSplitterFetch.nStartPos); %H:!/'45
output.writeLong(fileSplitterFetch.nEndPos); WL>"hkx
} b afYjF< 3
output.close(); %lvSO/F+
} hhwV)Z
catch(IOException e){e.printStackTrace ();} d6_ CsqV
catch(Exception e){e.printStackTrace ();} D:%v((Ccw
} (fq>P1-
zd+8fP/UB
|d8/ZD
//读取保存的下载信息（文件指针位置） 2/I^:*e
private void read_nPos() CFVe0!\
{ &a O3N
try{ G|.>p<q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <pz;G}
int nCount = input.readInt(); $U<xrN>O
nStartPos = new long[nCount]; ,Xao{o(
nEndPos = new long[nCount]; Mk7#qiPo
for(int i=0;i<nStartPos.length;i++) m(?M]CH(A
{ Hl]3F^{
nStartPos = input.readLong(); .' #_Z.zr
nEndPos = input.readLong(); KyDQ<Dq&
} =6/0=a[
input.close(); r..\(r
} 0,,x|g$TpT
catch(IOException e){e.printStackTrace ();} C:W}hA!
catch(Exception e){e.printStackTrace ();} !J.qH%S5
} m7fmQUk
U$qSMkj6RK
faThXq8B
private void processErrorCode(int nErrorCode) :o=[Zp~B4d
{ POdG1;)
System.err.println("Error Code : " + nErrorCode); 1S<V,9(
} fH>]>2fS
jg#%h`
wR1M_&-s
//停止文件下载 $TWt[
public void siteStop() ?-Fp rC
{ ?~;G)5
bStop = true; ~[Mm0L}8
for(int i=0;i<nStartPos.length;i++) GYZzWN}U
fileSplitterFetch.splitterStop(); (@~d9PvB>
!XQG1!|ww
MJb!+E+
} Uk5jZ|
} RD<l<+C^~
//负责部分文件的抓取 UuW"
**FileSplitterFetch.java Ydh]EO0'
*/ 36e!je
package NetFox; hQvSh\p
l$z\8]x
cOq^}Ohan
import java.io.*; _da>=^hFJ
import java.net.*; W& w-yZ
pX+`qxF\
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public class FileSplitterFetch extends Thread { O:WFh;c
,vl][MhM
)EcE{!H6+
String sURL; //File URL Ag^Cb'3X
long nStartPos; //File Snippet Start Position z`]'~
long nEndPos; //File Snippet End Position Yu`b[]W
int nThreadID; //Thread's ID t L}i%7
boolean bDownOver = false; //Downing is over Y&'Bl$`
boolean bStop = false; //Stop identical G ,An8GR%&
FileAccessI fileAccessI = null; //File Access interface k/ls!e?
Tt<Ry'Z$3
:VX?j3qW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QD-#sU]
{ 22)2olU
this.sURL = sURL; 7FMO''x
this.nStartPos = nStart; aHvTbpJ
this.nEndPos = nEnd; 7'k+/rAO
nThreadID = id; (%D*S_m'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7g[T#B'/x,
} " P c"{w
%s6|w=.1
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public void run() 0ZlF#PJA
{ ]^uO3!+
while(nStartPos < nEndPos && !bStop) LSS3(l[,:
{ TU&gj1
17 Hdj
4Bsx[~ u&
try{ 8xW_N"P.>
URL url = new URL(sURL); B0T[[%~3M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :$lx]
httpConnection.setRequestProperty("User-Agent","NetFox"); -y;SR+
String sProperty = "bytes="+nStartPos+"-"; -L}crQl.'c
httpConnection.setRequestProperty("RANGE",sProperty); 89?$xm_m
Utility.log(sProperty); Xkk m~sM6
eYLeytF]Uy
|t5K!?{i
InputStream input = httpConnection.getInputStream(); ?KDI'>"-v
//logResponseHead(httpConnection); R-+k>_96|
X!KjRP\\
sluR@[l
byte[] b = new byte[1024]; l:5x*QSX
int nRead; *"2TT})
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l_Mi'}j
{ .gh3"
nStartPos += fileAccessI.write(b,0,nRead); L}7c{6!F7
//if(nThreadID == 1) -SnP+X!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n.Iu|,?q
} icLf;@
^NKB
*_ {w0U)
Utility.log("Thread " + nThreadID + " is over!"); |#fqHON
bDownOver = true; )o-rg
//nPos = fileAccessI.write (b,0,nRead); HdQd =q(
} ~_OtbNj#
catch(Exception e){e.printStackTrace ();} `VM@-;@w
} !)FM/Xj,o
} 8pp^ w
}@>=,A4Y
W7r1!/ccj
//打印回应的头信息 dt%waM!
public void logResponseHead(HttpURLConnection con) C%}}~Y
{ gh>'O/9
for(int i=1;;i++) <1cYz\/!M
{ *J&XM[t
String header=con.getHeaderFieldKey(i); tEhYQZ
if(header!=null) {L^b['h@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); K"B2 SsC
Utility.log(header+" : "+con.getHeaderField(header)); \q(DlqTqs
else {fW(e?8)
break; /X>Fn9mM
} Pi7vuOJr8
} pVbgjJI
?UuJk
cD5c&+,&I
public void splitterStop() (lBgWz
{ ASME~]]?
bStop = true; c~bi ~ f
} 7/%{7q3G>
oju)8H1o#
qP@d)XRQ
} ^o^[p %
r^3/Ltd5/
7.@$D;L9
/* GAG=4g
**FileAccess.java QwPLy O
*//文件访问(定位，写) .4DX/~F
package NetFox; ~7a(KJgvd"
import java.io.*; GZXBzZ}
RQiGKz5
PEqO<a1Z8
public class FileAccessI implements Serializable{ ~$xLR/{y
WxwSb`U|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _EMq"\ND
RandomAccessFile oSavedFile; -v"\WmcS
long nPos; r:Uqtqxh
/;>U0~K
K8xwPoRL
public FileAccessI() throws IOException G&8)5d[
{ {nTQc2T?;
this("",0); Uv|z c
} VQA}!p
|L|)r)t
CGmObN8~'F
public FileAccessI(String sName,long nPos) throws IOException M\\t)=q
{ ;o*n*N
oSavedFile = new RandomAccessFile(sName,"rw"); 1haNca_6,
this.nPos = nPos; mRVE@pc2X
oSavedFile.seek(nPos); XwWp4`Fd
} n-iy;L^b
bV|(V>
]r++YIg!j
public synchronized int write(byte[] b,int nStart,int nLen) 4JF)w;X}
{ mHcxK@qw
int n = -1; e`gOc*
try{ |Yq0zc!
oSavedFile.write(b,nStart,nLen); C/AqAW1
n = nLen; m]LR4V6k|
} "o.V`Bj
catch(IOException e) %@JNX}Y'
{ +|6 '7Z(9
e.printStackTrace (); 'wh2787
} 5m2`$y-nb
fT)u`voE,
ia=eFWt.
return n; i$MYR @
} \GA6;6%Oo
s%Ez/or(T
I{>U7i 5
} {|)u).n|
}py6H[
9e^HTUFbG
/* $x_6 .AOZ,
**SiteInfoBean.java :9`'R0=i^
*/ llG^+*Y8t
package NetFox; .-Y3oWV
(pY'v/a-
w#V{'{DKp
public class SiteInfoBean { nT UKA
)nJo\HFXv
% H"A%
private String sSiteURL; //Site's URL 1O" Mo
private String sFilePath; //Saved File's Path gT 8^
private String sFileName; //Saved File's Name }Ej^M~Vv
private int nSplitter; //Count of Splited Downloading File 00s&<EM
)na8a!
mDJF5I
public SiteInfoBean() 0XwDk$l<
{//nSplitter的缺省值为5 We7~tkl(
//default value of nSplitter is 5 ]WLQ q4q
this("","","",5); m$glRs @
} o)w8 ]H/
"YIrqk
"6.JpUf
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :4o08M%
{ i={ :6K?^
sSiteURL= sURL; q:OSQ~U_
sFilePath = sPath; h@nNm30i
sFileName = sName; w&6c`az8
this.nSplitter = nSpiltter; EBF608nWfW
$i# 1<Qj
"T>74bj_|Q
} K@ZK@++
:]?y,e%xu,
RRYm.dMIw
public String getSSiteURL() `o7m)T')
{ wSrq?U5q
return sSiteURL; VlGg?
} JzhbuWwF-
:Ja]Vt
\U^0E> d
public void setSSiteURL(String value) ZY%]F,Y
{ ,,*i!%Adw
sSiteURL = value; 4]\f}
} T<!&6,N A
[c6I/U=-
yc|j]?
public String getSFilePath() eUiJl6^x
{ )ZkQWiP-
return sFilePath; ["'0vQ
} JryCL]
eURy]
]k2Jf}|
public void setSFilePath(String value) jI`1>>N&1
{ aBV{Xr~#(
sFilePath = value; %m\dNUz4g
} ,^dyS]!d$
_J<^'w^;%
*0y|0J+0
public String getSFileName() }=kf52Am,}
{ SG6@Rn*^
return sFileName; A]VcQ_e
} C)2Waj}
JaC =\\B
.gPE Qc+D
public void setSFileName(String value) #N`~.96
{ zP\n<L5
sFileName = value; #lA8yWxr
} &w{""'
kYxb@Zn=|
M[wd.\ %
public int getNSplitter() Q}G'=Q]Juz
{ aL63=y
return nSplitter; MMs#Y1dH
} 3q*y~5&I
Z<@Kkbj
A aLj.HR
public void setNSplitter(int nCount) "^A4!.
{ fJ!i%</V
nSplitter = nCount; d8 1u
} f<.43kv@
} d ]LF5*i
5B+>28G%
>Le L%$
/* _c}@Fi+E
**Utility.java 11Kbj`sRZ
*/ |RUx)&
package NetFox; hr%O4&sa
\k?uh+xl
wRwTN"Yg
public class Utility { y#\jc4F_a
$Iuf(J-5[
WBS~e
public Utility() >YPC&@9
{ G\8ps~3T
OoKzPePWji
LqnN5l@_B
} &h=O;?dO
#BQ7rF7CNE
//线程睡眠 *%JncK'
public static void sleep(int nSecond) : `D[0
{ l#P)9$%
try{ LM:|Kydp3
Thread.sleep(nSecond); K/;FP'.
} -!E))|A
catch(Exception e) g?V>+oMx
{ nBs%k!RR
e.printStackTrace (); qx0RCP /s
} as\6XW$;Q
} W@NM~+)e
x\ieWF1
//日志 O[O`4de9
public static void log(String sMsg) 9W$d'IA
{ +QNFu){G
System.err.println(sMsg); D3#/*Ky
} %JBFG.+
+hdD*}qauC
|*079v
public static void log(int sMsg) [t55Kz*cD
{ 5ru&In&
System.err.println(sMsg); C2GF N1i
} I8r5u=PH
} X#9}|rT56
HC,YmO:df"
1 h(oty2p
/* uWw4l"RK`
**TestMethod.java Skgvnmk[U
*/ 41luFtE9
package NetFox; j?Ki<MD1
[;M31b3
[u[`!L=
public class TestMethod { f$a%&X6"-
k)D:lpxv
uLV@D r
public TestMethod() ~@ZdO+n?
{ ///xx/weblogic60b2_win.exe (uG.s%I
try{ QF/A-[V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3nt&Sf
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T1bPI/
SiteFileFetch fileFetch = new SiteFileFetch(bean); et";*EZJX
fileFetch.start(); ,<$6-3sC-
} c)8V^7=Q
catch(Exception e){e.printStackTrace ();} &0*l=!:G^
}J}a;P4
c-z2[a8
} -L>\58`
MCHRNhb9
q0Fq7rWP
public static void main(String[] args) ZN!OM)@:!
{ ?vL\VI9
new TestMethod(); =G9%Hz5~:
} a~YFJAkg9
} L-_dq0T
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