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)); }+";W)R
} /cM<
for(int i=0;i<nEndPos.length-1;i++) S?_/Po|
{ *[K\_F?^h
nEndPos = nStartPos[i+1]; /3`#ldb%}
} FrXFm+8 F
nEndPos[nEndPos.length-1] = nFileLength; ;T6{J[ h
} U"\$k&
} )pELCk
6apK]PT
`D)ay
//启动子线程 -ZwQL="t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ')ZxWYT O^
for(int i=0;i<nStartPos.length;i++) v|r\kr k
{ rS1mBrqD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T*YbmI]4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c4Q{
nStartPos,nEndPos,i); <5rs~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XwWp4`Fd
fileSplitterFetch.start(); n-iy;L^b
} bV|(V>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oj\av~cI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ti6\~SY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v[4A_WjT
nEndPos = " + nFileLength); $qOV#,@
// fileSplitterFetch[nPos.length-1].start(); IoUQ~JviA
6b&<5,=d:
wXdtY
//等待子线程结束 Hjl{M>z
//int count = 0; qIEe7;DO
//是否结束while循环 xe ng`!
boolean breakWhile = false; zGKDH=Yy ;
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022nn-~
while(!bStop) mY[s2t
{ g+shz{3zvz
write_nPos(); pe(31%(h
Utility.sleep(500); %g1{nGah
breakWhile = true; "p]bsJG
`R:p-"'b
oJ|8~:)
for(int i=0;i<nStartPos.length;i++) (Ic{C5'
{ %tx~CD
if(!fileSplitterFetch.bDownOver) ?M2#fD]e
{ !&4<"wQ
breakWhile = false; "XQj~L
break; }<?1\k
} O7r<6(q(
} 9[.vtk\iyH
if(breakWhile) a3}#lY):
break; GMc{g
|.kYomJ
Hj&mwn]
//count++; pPr/r&r
//if(count>4) !YUMAp/
// siteStop(); #XSs.i{
} cH$zDm1
/>1Ndj
(S~|hk^
System.err.println("文件下载结束！"); 43_;Z| T
} jTVh`d<N
catch(Exception e){e.printStackTrace ();} We7~tkl(
} m$glRs @
l+# l\q%l
UuDT=_1Sh
//获得文件长度 B_;W!
public long getFileSize() BI9~%dm
{ 77y_?di^I
int nFileLength = -1; SCbN(OBN!
try{ z=ItKoM*<
URL url = new URL(siteInfoBean.getSSiteURL()); MF+J3)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~lB im$o
httpConnection.setRequestProperty("User-Agent","NetFox"); j9)WInYc:
3@u<Sa
GE+%V7
int responseCode=httpConnection.getResponseCode(); tnx)_f
if(responseCode>=400) n<Vq@=9AE
{ "YIrqk
processErrorCode(responseCode); Y6LoPJ
return -2; //-2 represent access is error ?~G D^F
} X6_m&~}15
UdBP2lGd
\9[_*
String sHeader; hVvPI1[2
Z<7FF}i
j@OGl&'^-
for(int i=1;;i++) \5g7_3,3W
{ %;5AF8#c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); OyTEd5\3
//Utility.log(in.readLine()); lZyxJDZ A
sHeader=httpConnection.getHeaderFieldKey(i); t- Rp_2t
if(sHeader!=null) ?Bg<74
{ ` oBlv
if(sHeader.equals("Content-Length")) REd"}zDI
{ ?QzA;8H
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z#8O)GK
break; YyI4T/0s_
} b"`Vn,
} :mwNkT2et
else 4]\f}
break; T<!&6,N A
} [c6I/U=-
} yc|j]?
catch(IOException e){e.printStackTrace ();} eUiJl6^x
catch(Exception e){e.printStackTrace ();} )ZkQWiP-
["'0vQ
M,0@@:
Utility.log(nFileLength); $@8$_g|Wz
Ift @/A
YXD6GJWo
return nFileLength; 3$YgGum
} ^QX3p,Y
WM8 Ce0E
W'2a1E
//保存下载信息（文件指针位置） $6p_`LD0
private void write_nPos() n0o'ns
{ \k6Ho?PL
try{ +.i?UHNB
output = new DataOutputStream(new FileOutputStream(tmpFile)); J{98x zb
output.writeInt(nStartPos.length); !1MSuvWP
for(int i=0;i<nStartPos.length;i++) :5/P{Co(
{ k!/"J ;
// output.writeLong(nPos); zbL!q_wO
output.writeLong(fileSplitterFetch.nStartPos); r[P5 ufy2]
output.writeLong(fileSplitterFetch.nEndPos); G]q1_q4P1?
} W/dl`UDY
output.close(); XqD/~_z;
} }*+?1kv
catch(IOException e){e.printStackTrace ();} 'BE &lW
catch(Exception e){e.printStackTrace ();} {Vz.| a[T
} .r~!d|
.]_Ye.}
z6B(}(D
//读取保存的下载信息（文件指针位置） jR/YG ru
private void read_nPos() v634{:'e
{ B1]5%B
try{ [<~1.L^I
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W}6(;tI
int nCount = input.readInt(); _sU|<1
nStartPos = new long[nCount]; l V[d`%(
nEndPos = new long[nCount]; {3RY4HVT?
for(int i=0;i<nStartPos.length;i++) `N0Mm7
{ AF5$U8jf
nStartPos = input.readLong(); !f~ =p
nEndPos = input.readLong(); ]fH U/%
} 9Vp|a&Ana
input.close(); uus}NZ:*l
} E|u#W3-:
catch(IOException e){e.printStackTrace ();} 1i;-mYGaMn
catch(Exception e){e.printStackTrace ();} ;lqtw]4v
} ,Y~{RgG
np|3 os
r3a$n$Qw
private void processErrorCode(int nErrorCode) imcq H
{ hQ!slO
System.err.println("Error Code : " + nErrorCode); kz]vXJ
} z@E-pYV
pDr%uL
%U]_1"d,<\
//停止文件下载 ]d#Lfgo
public void siteStop() 3`@alhD'
{ Vl;GQe
bStop = true; w9D<^(_}/
for(int i=0;i<nStartPos.length;i++) w*.q t<rH)
fileSplitterFetch.splitterStop(); Yk',a$.S
]"SH pq
2ye^mJ17
} w3lR8R]
} 5IeF |#g
//负责部分文件的抓取 2mS3gk
**FileSplitterFetch.java e%VJ:Dj
*/ <b74L
package NetFox; et|P5%G
A|sTnhp~
i_OoR"J%
import java.io.*; fm2,Mx6
import java.net.*; 5>.)7D%
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public class FileSplitterFetch extends Thread { ODn6%fp%
rK%<2i
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String sURL; //File URL 5Z{h!}Y
long nStartPos; //File Snippet Start Position %AbA(F
long nEndPos; //File Snippet End Position J{$+\
int nThreadID; //Thread's ID +RexQE
boolean bDownOver = false; //Downing is over x2B~1edf
boolean bStop = false; //Stop identical Sbub|
FileAccessI fileAccessI = null; //File Access interface #W#GI"K
;Ab`b1B
*ayn<Vlh`^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mQt';|X@
{ %1ofu,%
this.sURL = sURL; 6x KbK1W
this.nStartPos = nStart; }>vf(9sF`
this.nEndPos = nEnd; wD>tR SW
nThreadID = id; SX)giQLU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c)8V^7=Q
} &0*l=!:G^
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7 }`c:u~j
public void run() qJQE|VM&
{ |B&KT
while(nStartPos < nEndPos && !bStop) G5W6P7-<X
{ UeB8|z
Z&W|O>QTl
ZbTU1Y/'
try{ *z4n2"<l
URL url = new URL(sURL); qM F'&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '$u3i #.\
httpConnection.setRequestProperty("User-Agent","NetFox"); 1Sox@Ko
String sProperty = "bytes="+nStartPos+"-"; E@\e37e
httpConnection.setRequestProperty("RANGE",sProperty); X%"P0P
Utility.log(sProperty); uG2(NwOL
o)'u%m
$ wGDk
InputStream input = httpConnection.getInputStream(); y'?|#%D
//logResponseHead(httpConnection); /G$8j$
J<x?bIetj
U,"lOG'
byte[] b = new byte[1024]; i:`ur
int nRead; ? lC. Pq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) XQ.czj
{ $Gb] K{e
nStartPos += fileAccessI.write(b,0,nRead); _+0l+a*D
//if(nThreadID == 1) @AUx%:}0Y:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )c=R)=N
} xZjl_bJ
7|3Qcn7P)@
jR7 , b5
Utility.log("Thread " + nThreadID + " is over!"); <N"t[N70;
bDownOver = true; p D!IB`cA4
//nPos = fileAccessI.write (b,0,nRead); IdTeue
} 4kGA`XhS*
catch(Exception e){e.printStackTrace ();} n k]tq3.[
} v0!>":
} >B$ZKE
F\!;}z
\Ku=a{Ne
//打印回应的头信息 9_'xq.uP
public void logResponseHead(HttpURLConnection con) @`2<^-r\
{ 'U]= T<
for(int i=1;;i++) Q&:%U
{ y XZZ)i_
String header=con.getHeaderFieldKey(i); E",s]
if(header!=null) 5)4*J.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *leQd^47
Utility.log(header+" : "+con.getHeaderField(header)); 3/8o)9f.
else DUf=\p6`f
break; m`C(y$8fU
} V x1C4
} j &)Xi^^
:P`sK&b_
RC Fb&,51
public void splitterStop() GL&ri!,
{ f9H;e(D9]
bStop = true; "m +Eu|{
} /b,+YyWi%
XNwY\y
iRo UM.%
} [7B:{sH
1\q(xka{
c38RE,4U
/* (8o~ XL
**FileAccess.java B1m@
*//文件访问(定位，写) \~:Kp Kq
package NetFox; 3:jKuOX
import java.io.*; A<^IG+Q,B7
o:#l r{
9F)v=
public class FileAccessI implements Serializable{ W>eJGZ<
b_-ESs]g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +<6L>ZAL
RandomAccessFile oSavedFile; STu!v5XY}-
long nPos; g[Ah> 5
;[WW,,!Y
%@q52ZQ
public FileAccessI() throws IOException tu6oa[s
{ RL |.y~
this("",0); 9Q-/Yh
} o%h"gbvMY!
N( E\
;RZ@t6^
public FileAccessI(String sName,long nPos) throws IOException W3*BdpTw
{ @B5@3zYs
oSavedFile = new RandomAccessFile(sName,"rw"); [P8Y
this.nPos = nPos; +Y(cs&V*
oSavedFile.seek(nPos); t3u"2B7oG
} bO1J#bcZ
raY5 nc{
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public synchronized int write(byte[] b,int nStart,int nLen) 0trVmWQ8
{ w=d#y )1
int n = -1; 8lI#D)}
try{ mk_cub@
oSavedFile.write(b,nStart,nLen); 7{f&L'
n = nLen; +o(t5O[G
} R'qB-v.
catch(IOException e) _z\oDd`'
{ 84)$ CA+NX
e.printStackTrace (); 3v;o`Em&
} ??12 J#
~\4l*$3(^
)v;>6(
return n; ('Wo#3b$
} )u]J`.OA
4;Z`u.1
ZH/^``[.
} \k0%7i[nZ/
f7{E(,
OGg9e
/* Htl6Mr*{
**SiteInfoBean.java ^DXERt&3
*/ }$#e&&)n
package NetFox; +mhYr]Z
=$Sf]L
(f5!36mz
public class SiteInfoBean { J|_&3@r
^M6v;8EU
[ik D4p=
private String sSiteURL; //Site's URL iN+Dmq5
private String sFilePath; //Saved File's Path LP_d}ve
private String sFileName; //Saved File's Name W+BM|'%}|
private int nSplitter; //Count of Splited Downloading File N}nU\e6 Y
f'F:U^
H`]nY`HYg
public SiteInfoBean() yw"FI!M
{//nSplitter的缺省值为5 cy*Td7)/
//default value of nSplitter is 5 fF[n?:VV
this("","","",5); |TF,Aj
} \D?6_ ,O
f}^}d"&F
3!Zd]1$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P~redX=t@
{ GV6!`@<
sSiteURL= sURL; l*uNi47|
sFilePath = sPath; qd~)Ya1
sFileName = sName; \.myLkm
this.nSplitter = nSpiltter; 3ag*dBbs
MHVqRYz
78#je=MDg
} #6fp"
H&E c*MT
8U0y86q>)E
public String getSSiteURL() "p.MJxH
{ #<0%_Ca
return sSiteURL; tvP_LNMF
} ;4 R1
|@]J*Kh
DF%\1C>
public void setSSiteURL(String value) * gr{{c
{ kLR4?tX!
sSiteURL = value; m46Q%hwV
} sI/Hcm
\ lP c,8)
"@W0Lk[
public String getSFilePath() yU\&\fD>j
{ D#x D-c
return sFilePath; go m<V?$
} Dk&cIZ43
);@Dr!H
E:4`x_~qQ
public void setSFilePath(String value) uTA /E9OY
{ F)j-D(c4
sFilePath = value; QOlm#S
} "^ydoRZ
H!4!1J.=xw
;TF(opW:
public String getSFileName() Bt[`p\p@
{ z!)_'A
return sFileName; SWUHHl
} wg^#S
&fdH HN
m;WUp{'
public void setSFileName(String value) "@Bc eD
{ -2o4v#d
sFileName = value; VxLq,$B76
} (WR&Vt4Rh
;i^p6b j
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public int getNSplitter() 49nZWv48"_
{ gZ%B9i:
return nSplitter; ~KDx
} W tnZF]1:u
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rhMsZ={M
public void setNSplitter(int nCount) IQMk:
{ A@j;H|
nSplitter = nCount; Um)0jT
} '$ ~.x|
} l2+qP{_4
2JYp.CJv
+G"=1sxJ
/* Y]{<IF:
**Utility.java p H5IBIf'
*/ Zd1+ZH
package NetFox; $/}*HWVZ
v$K`C;
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public class Utility { W*QD'
e7t).s)b{
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public Utility() VW<s_
{ <P3r+ 1|R
e,={!P"f
bESmKe(
} -TU7GCb=
C (vi ns
//线程睡眠 >T%Jlj3ZG
public static void sleep(int nSecond) 8Z4d<DIJ
{ $^.LZ1Jd
try{ 3%/]y=rA
Thread.sleep(nSecond); Vl{CD>$,
} $yIcut7
catch(Exception e) <^UB@'lCm
{ 9U>ID{
e.printStackTrace (); jj0@ez{3
} :4}?%3&;
} 4;M
5@tpJ8E8$
//日志 }Jk.c~P)
public static void log(String sMsg) 7ks09Cy
{ Ms<^_\iPN
System.err.println(sMsg); GxLoNVr
} (ivV[
82&JYx
V5i_\A
public static void log(int sMsg) ^TyusfOz
{ fPiq
System.err.println(sMsg); _{8f^@I"+
} sRE$*^i
} Un]`Gd]:
]cc4+}L~
|b;}' *
/* Q nDymVF
**TestMethod.java q =b.!AZy
*/ Oo`P +S#
package NetFox; n]}+ :
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n4 KiC!*i0
public class TestMethod { -WB?hmx
/&$'v:VB
U)zd~ug?m
public TestMethod() Yi{[llru
{ ///xx/weblogic60b2_win.exe $G"PZ7
try{ .bB_f7TH.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aP!a?xq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A]Zp1XEG
SiteFileFetch fileFetch = new SiteFileFetch(bean); r[eZV"
fileFetch.start(); k*-_CO-h
} D=mU!rjr1
catch(Exception e){e.printStackTrace ();} Lbq"( b
_0)#-L>xKF
X9/V;!
} C(3yJzg>y
i`gsT[JQRX
P~#!-9?
public static void main(String[] args) ?#qA>:2,
{ V3$!`T}g4
new TestMethod(); G`R Ed-Z[
} W:3u$LTf*f
} b5_A*-s$M
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