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)); a8WWFAC[
} ~dO+kD
for(int i=0;i<nEndPos.length-1;i++) d*YVk{s7V
{ (ZPl~ZO
nEndPos = nStartPos[i+1]; Ypx5:gm|J
} lw]uH<v
nEndPos[nEndPos.length-1] = nFileLength; 1[yy/v'q
} +\doF
} z''ejq
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HNRAtRvnY
//启动子线程 |oWl9j]Z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; MY60%
for(int i=0;i<nStartPos.length;i++) +v2)'?BS
{ T@Bu Fr`]<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E<ILZpP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $>8O2p7W
nStartPos,nEndPos,i); w%?Zb[!&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (@1>G ^%
fileSplitterFetch.start(); 2 \<u;9
} %[4u #G`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s{Og3qUy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); y6dQ4Whv&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {Rdh4ZKh
nEndPos = " + nFileLength); g~ii^[W
// fileSplitterFetch[nPos.length-1].start(); !kG|BJ$j
ih|;H:"^
Y(
//等待子线程结束 uHsLlfTn
//int count = 0; o}&{Y2!x
//是否结束while循环 nC%<BatQ
boolean breakWhile = false; Pl. y9g~
4ClSl#X#i
EKD#s,(V*X
while(!bStop) MgP&9
{ S n<X
write_nPos(); y"Pd>61h
Utility.sleep(500); Rt5,/Q0
breakWhile = true; 1:iB1TclP
NBXhcfF
=:Yrb2gP_\
for(int i=0;i<nStartPos.length;i++) 1 0zw}1x
{ mrq,kwM
if(!fileSplitterFetch.bDownOver) [7Q%c!e$*
{ gKY6S?
breakWhile = false; Uqz.Q\A
break; @tJ4^<`P{
} JljCI@
} 0~EGrEt
if(breakWhile) t 9t '9
break; c|d,:u#
Qcks:|5
<@# g2b
//count++; h-//v~V)
//if(count>4) HYmUD74FR
// siteStop(); z`YC3_d
} tUuARo7#
L }3eZ-
+~BP~
System.err.println("文件下载结束！"); 6uv~.-T<l
} ,a?oGi
catch(Exception e){e.printStackTrace ();} Q)y5'u qZ
} -Bl^TT
sYo&@~T
AN6Q~%,
//获得文件长度 MRw4?HqB
public long getFileSize() _Rb2jq(&0
{ q2r$j\L%
int nFileLength = -1; RJUIB
try{ $}r.fji,c
URL url = new URL(siteInfoBean.getSSiteURL()); j>e RV ol
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BVj(Q}f8
httpConnection.setRequestProperty("User-Agent","NetFox"); o<iU;15
O_ZYm{T[7
$=Ns7Sbup
int responseCode=httpConnection.getResponseCode(); 6bc\ )n`
if(responseCode>=400) .j&#
{ u#rbc"
processErrorCode(responseCode); _G-y{D_S&
return -2; //-2 represent access is error BdiV
} AC'_#nPL#
*Ti"8^`6
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String sHeader; 83I 5n&)
cC>Svf[CzK
oPF]]Imu
for(int i=1;;i++) }IZw6KiN
{ P$0c{B4I
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); hdi0YL
//Utility.log(in.readLine()); i721(1
sHeader=httpConnection.getHeaderFieldKey(i); 0MroHFh9`
if(sHeader!=null) ~@Q]@8Tv\
{ Vs{\ YfF
if(sHeader.equals("Content-Length")) 8Z_ 4%vUBg
{ :b(W&iBWhI
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |6b~c{bt
break; oQ,<Yx%E3
} )qw;KG0F
} <qpzs@
else DpvHIE:W
break; 3(\D.Z
} 9]w?mHslE
} '7PaJj=Nx
catch(IOException e){e.printStackTrace ();} {+7FBdxVB
catch(Exception e){e.printStackTrace ();} !&hqj$>-}
c`p'5qz
:>;F4gGVG
Utility.log(nFileLength); E/a2b(,Tg
+)WU:aKI
A]'jsv!+
return nFileLength; w(aHB8T
} ;m#4Q6k)V?
;aWk-
Vc;[0iB
//保存下载信息（文件指针位置） =t)qy5
private void write_nPos() ,0,FzxX0!
{ aK -x{
try{ rvy%8%e?
output = new DataOutputStream(new FileOutputStream(tmpFile)); RU4X#gP4Vh
output.writeInt(nStartPos.length); Jj+Q2D:
for(int i=0;i<nStartPos.length;i++) ?YS>_MN
{ rG6G~|mS
// output.writeLong(nPos); 6Q [
output.writeLong(fileSplitterFetch.nStartPos); nL/]Q'(5
output.writeLong(fileSplitterFetch.nEndPos); zA>X+JH>iw
} =hFY-~U
output.close(); \q1tT!]
} w/ rQOHV{
catch(IOException e){e.printStackTrace ();} HrvyI)4{
catch(Exception e){e.printStackTrace ();} ~[t#$2d}
} cI\[)5&
A| A#|D
X:g5;NT
//读取保存的下载信息（文件指针位置） aMhVO(+FW
private void read_nPos() Dk^AnMx%_
{ Wy7w zt
try{ `HQ)][
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XyE$0i~t
int nCount = input.readInt(); zU~ Ff"<
nStartPos = new long[nCount]; [QgP6f]=
nEndPos = new long[nCount]; 6d6cZGS[:
for(int i=0;i<nStartPos.length;i++) VnsV&cx
{ b-VygLN
nStartPos = input.readLong(); d7vPZ_j^z
nEndPos = input.readLong(); [5?Dov^j3
} e7@ m i
input.close(); %5gdLm!p
} oc( '!c
catch(IOException e){e.printStackTrace ();} ^%9oeT{
catch(Exception e){e.printStackTrace ();} n>q!m@ }<
} fF0i^E<
Q*>)W{H&)
"Bf8mEmp
private void processErrorCode(int nErrorCode) b+|Jw\k
{ r9_ ON|
System.err.println("Error Code : " + nErrorCode); C(G.yd
} >[;@ [4}
1 6zxPSTr}
`-pwP
//停止文件下载 /"gRyv
public void siteStop() =Z:]%
{ ?/3wO/7[
bStop = true; $3HqVqF^R
for(int i=0;i<nStartPos.length;i++) B&a{,.m&q6
fileSplitterFetch.splitterStop(); 0AQ4:KV(Y
5 qfvHQ ~M
'OtTq8G
} 3s!6rT_=)d
} 9BtGzI\
//负责部分文件的抓取 Hloe7+5UD
**FileSplitterFetch.java N^rpPq
*/ !+PrgIp>
package NetFox; rc8HZ
~{Iw[,MJ
.A< HM}
import java.io.*; kuH%aM<R
import java.net.*; <J;O$S
jV sH
]XEyG7D
public class FileSplitterFetch extends Thread { HqWWWCWal
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String sURL; //File URL &}p\&4
long nStartPos; //File Snippet Start Position ]%6%rq%9C
long nEndPos; //File Snippet End Position f 3H uT=n
int nThreadID; //Thread's ID caQ1SV^{9
boolean bDownOver = false; //Downing is over #H~55))F
boolean bStop = false; //Stop identical \|Af26
FileAccessI fileAccessI = null; //File Access interface ;O hQBAC
#7O7O~
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |M7C=z='
{ }h;Z_XF&
this.sURL = sURL; 8UjIC4'
this.nStartPos = nStart; %Y ZCdS
this.nEndPos = nEnd; K:U=Y$x
nThreadID = id; NRx 7S9W
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;I*t5{
} \7LL neq
MM32\}Y6
~%*l>GkP*
public void run() #-B<u-
{ PL=v,NB
while(nStartPos < nEndPos && !bStop) RkG?R3e
{ )W\)kDh!
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6n2RTH
try{ I'P|:XKI
URL url = new URL(sURL); Hi[lN7ma8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oi0O4J%H
httpConnection.setRequestProperty("User-Agent","NetFox"); eW8cI)wU
String sProperty = "bytes="+nStartPos+"-"; {Ycgq%1>]
httpConnection.setRequestProperty("RANGE",sProperty); Lmjd,t
Utility.log(sProperty); MlWKfe<
jF;<9-m&
k H65k (
InputStream input = httpConnection.getInputStream(); 6E) T;R(@
//logResponseHead(httpConnection); %@:>hQ2;
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&;ddnxFI
byte[] b = new byte[1024]; bq7+l4CGTv
int nRead; A/=cGE
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jW#dUKS(
{ w-WAgAch
nStartPos += fileAccessI.write(b,0,nRead); "-S!^h/v
//if(nThreadID == 1) 3)VO{Cj!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x}a?B
} {@KLN<
waC i9
&H# l*
Utility.log("Thread " + nThreadID + " is over!"); ]Qe~|9I
bDownOver = true; TQeIAy
//nPos = fileAccessI.write (b,0,nRead); 6'*6tS
} E*)A!2rlK
catch(Exception e){e.printStackTrace ();} O8hx}dOjA
} aEdMZ+P.
} .nIGs'P
,Z|O y|+'
,eebO~7vB
//打印回应的头信息 qX5]\nX&G
public void logResponseHead(HttpURLConnection con) _RcEfT
{ rMG[,:V
for(int i=1;;i++) <*iFVjSI(
{ }kAE
String header=con.getHeaderFieldKey(i); 0e>?!Z E
if(header!=null) A["6dbvv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &z3_N
Utility.log(header+" : "+con.getHeaderField(header)); FBP #_"z
else r8R7@S2V'
break; :Dr4?6hdr
} >*/ |tL
} )+G0m,n
>.39OQ#
uR")@Tc
public void splitterStop() 7g8\q@',
{ vIi&D;
bStop = true; i]zh8|">
} U#Kw+slM
+:#g6(P]
4myikeUR_
} 9[{q5
#/(L.5d[
p^{yA"MQ
/* S% ptG$Z
**FileAccess.java T8LvdzS
*//文件访问(定位，写) /;TD n>lq
package NetFox; ZnbpIJ8cV
import java.io.*; L(y~ ,Kc
KPK`C0mg@k
|[V6R\l39
public class FileAccessI implements Serializable{ UQ e1rf
K=sk1<>)m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M;-FW5O't
RandomAccessFile oSavedFile; ,=ju^_^sA
long nPos; ;h~kB
u8~5e
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public FileAccessI() throws IOException ^SUo-N''
{ &@&^k$du8q
this("",0); 0,LUi*10
} IxlPpS9Wx
$iy(+}
Y^?PHz'Go
public FileAccessI(String sName,long nPos) throws IOException /{ 8.Jcx$
{ fb]=MoiJ
oSavedFile = new RandomAccessFile(sName,"rw"); z_&T>ME
this.nPos = nPos; ^^Q>AfTR.
oSavedFile.seek(nPos); 1kc{`oL
} .fzns20u
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z\IZ5'
public synchronized int write(byte[] b,int nStart,int nLen) 2IDn4<`
{ # WL5p.
int n = -1; 7sJGB^vM
try{ kb*b|pWlO
oSavedFile.write(b,nStart,nLen); 3V/|"R2s
n = nLen; 0c#|LF_
} DVbY
catch(IOException e) wB*}XJah
{ 0vz!)
e.printStackTrace (); ;xE1#ZT
} }Tk*?tYt
B{_-k
Q mz3GH@wg
return n; s[/)v:
} Bk4|ik}
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} O%s?64^U
cp 7;~i3
YcuHYf5
/* cA B^]j
**SiteInfoBean.java ~M J3-<I
*/ hrnY0
package NetFox; N%8aLD
\E:l E/y
v%2Jm!i+
public class SiteInfoBean { 8J#TP7;
;hU~nj+{
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private String sSiteURL; //Site's URL /T/7O
private String sFilePath; //Saved File's Path h`p9H2}0
private String sFileName; //Saved File's Name c:z<8#A}
private int nSplitter; //Count of Splited Downloading File Xc@%_6
p[gq^5WuC
Uv/?/;si
public SiteInfoBean() u'EzYJ7
{//nSplitter的缺省值为5 s av
//default value of nSplitter is 5 \rf2Os
this("","","",5); 8Ow0A
} qw%wyj7
H;eOrX{GT
5U&?P
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W_N!f=HW
{ ^c]lEo
sSiteURL= sURL; p=U5qM.O
sFilePath = sPath; rY&Y58./
sFileName = sName; vErlh:~e
this.nSplitter = nSpiltter; (|<.7K N
T8rf+B/.L
qy|si4IU8,
} -( ,iwFb
KFMEY\6\h
Syj7K*,%bZ
public String getSSiteURL() Z}'"c9oB
{ +'!vm6
return sSiteURL; j8Csnm0
} i.`RQZ$,/
(Q09$
HJu;4O($
public void setSSiteURL(String value) v(tr:[V
{ U$(AZ|0
sSiteURL = value; Z,osdF
} hd}"%9p
[8QE}TFic
%v(\;&@
public String getSFilePath() _:tisr{
{ aBLE:v
return sFilePath; "ujt:4p@
} l1qWl
`cgSyRD]
IuQY~!
public void setSFilePath(String value) n3kYVAgF
{ c|'hs
sFilePath = value; tCdgtZm
} Dab1^H!KT
"K8<X
EI29;
public String getSFileName() wb }W;C@
{ 3Yd)Fm
return sFileName; i+V4_`
} Rz!E=1Y$
e>kw>%3bl9
t3 q0|S
public void setSFileName(String value) =y/VrF.bV
{ r$*p
sFileName = value; <,Zk9 t&
} ;Vad| -
"yI)F~A
46dh@&U
public int getNSplitter() `q 4%
{ @,-xaZ[
return nSplitter; Iky'x[p,D
} uSs~P%@6|
^6~CA
[Uezi1I
public void setNSplitter(int nCount) Ve&(izIh
{ tF)aNtX4^
nSplitter = nCount; J0}OmNTzD
} :G|Jcl=r
} mB$r>G/'
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'(kySf[
/* EY(@R2~#J
**Utility.java Nvs8t%
*/ C,w$)x5kls
package NetFox; tLpDIA_8
bgd1j,PWbW
)#r]x1[Kn
public class Utility { G1Cn[F;e
v!ULErs
"6n~,$
public Utility() 3_IuK6K2
{ ;""V s6
:JqH.Sqk
g[j"]~
} +"a .,-f!
!h2ZrT9 _
//线程睡眠 @R?S-*o
public static void sleep(int nSecond) s} ,p>8
{ fw_V'l#\
try{ gQ*0Mk
Thread.sleep(nSecond); (?&X<=|"
} \{n]&IjA
catch(Exception e) Y*0%lq({H
{ oa+Rr&t'
e.printStackTrace (); :t]YPt
} =_8
} 5 %q26&
?T70C9
//日志 }(dhXOf\q
public static void log(String sMsg) Q5iuK#/
{ W z3y+I/&
System.err.println(sMsg); jGd{*4{3+
} G6Z2[Ej1
7[:9vY
'rU [V+
public static void log(int sMsg) $r9Sn
{ j"/i+r{"E
System.err.println(sMsg); o8RagSIo8
} 4W~pAruwr
} J \1&3r|R
6Ez}A|i
_;{n+i[
/* {Os$Uui37\
**TestMethod.java VLc=!W}
*/ O(h4;'/E
package NetFox; DTt/nmKAqJ
>"B95$x5
t*82^KDU
public class TestMethod { Txfu%'2)e
d5%A64?
+o!".Hp
public TestMethod() 0eQyzn*98
{ ///xx/weblogic60b2_win.exe 6YQ&+4
try{ 1Qtojph
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); fEWS3`Yy
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r@H<@Vuc
SiteFileFetch fileFetch = new SiteFileFetch(bean); EMmNlj6
fileFetch.start(); MSoLx' <
} M$ `b$il
catch(Exception e){e.printStackTrace ();} $VhUZGuG>
"CB*
j\("d4n%C
} h2zuPgz,
YL=?Nk/
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public static void main(String[] args) OOGqtA;
{ kz(%8qi8&
new TestMethod(); Ajr]&H4
} MZB0vdx
} +g<2t,
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