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)); >PH< N
} Fhi5LhWe+.
for(int i=0;i<nEndPos.length-1;i++) `Y\QUj
{ Ij$)RSPtH
nEndPos = nStartPos[i+1]; a&:>Ped"
} /a%KS3>V*
nEndPos[nEndPos.length-1] = nFileLength; 9<qx!-s2rr
} ZX]A )5G
} vUfO4yfdg
F=5kF/}x-z
Fs9W>*(
//启动子线程 #,Bj!'Q'-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; q5gP~*?
for(int i=0;i<nStartPos.length;i++) MVuP |&:n
{ 7X:hIl
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,A?v,Fs>O[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &O{t^D)F
nStartPos,nEndPos,i); d:3= 1x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <|dj^.^
fileSplitterFetch.start(); #[(0tc/
} #J3zTG(:@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ris-tdg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); c.6QhE
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,|QU] E @
nEndPos = " + nFileLength); Pd&,G$l
// fileSplitterFetch[nPos.length-1].start(); /]l f>\x1
s|p(KWo2U
Wlxk
//等待子线程结束 +ks$UvtY
//int count = 0; xx}'l:}2]
//是否结束while循环 L.Vq1RU\"
boolean breakWhile = false; 6fQ*X~| p
Q^kMCrp
OMxxI6h
while(!bStop) ~s0P FS7
{ v5gQ9
write_nPos(); %SFw~%@3&~
Utility.sleep(500); y(ldO;.
breakWhile = true; 6%z`)d
rOhA*_EG
nO%<;-=u\
for(int i=0;i<nStartPos.length;i++) #m_\1&g
{ t3M0La&
if(!fileSplitterFetch.bDownOver) KD9Ca $-
{ B4 <_"0
breakWhile = false; cG5$lB
break; ]:Wb1
} 9cbB[c_.
} 0YHYxn
if(breakWhile) &,Uc>L%m
break; 6vZt43"m?\
IBF.&[[S
Q)9369<A
//count++; [y$j9
//if(count>4) =1_jaDp
// siteStop(); ),z,LU Yf
} 8*"rZh}'
r$Kh3EEF`E
],!pp3U
System.err.println("文件下载结束！"); gZ~y}@Ly
} 1gL8$.B?
catch(Exception e){e.printStackTrace ();} vatx+)
} )/i4YLO
X^9t
mrX}\p
//获得文件长度 [29$~.m$Y
public long getFileSize() ^S3A10f,
{ !/[AQ{**T!
int nFileLength = -1; .Pqj6Ko9
try{ s')!<E+z\t
URL url = new URL(siteInfoBean.getSSiteURL()); \y<+Fac1S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pq@$&G
httpConnection.setRequestProperty("User-Agent","NetFox"); KF*B
]IL3$eR
7=AO^:=bx
int responseCode=httpConnection.getResponseCode(); C[^a/P`i
if(responseCode>=400) <`^>bv9
{ )vxVg*.Ee
processErrorCode(responseCode); 30e(4@!4vW
return -2; //-2 represent access is error s;~J2h[
} !Q\X)C
ye9QTK6$,
Pau&4h0
String sHeader; F&-5&'6G+
%_cg|yy
CA'hvXb.
for(int i=1;;i++) ZD iW72&Q
{ `7+tPbjs
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); CAcOWwDm
//Utility.log(in.readLine()); sz){uOI
sHeader=httpConnection.getHeaderFieldKey(i); q|m#IVc
if(sHeader!=null) )GQD*b
{ ntd ":BKi
if(sHeader.equals("Content-Length")) H7 o$O
{ ]g>T9,)l
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W\zL
break; 9p!dQx
} 5LnB]dW
} Qq6%53
else m mw)C"
break; KX&Od@cQ$
} )i?{;%^
} C&qDvvk
catch(IOException e){e.printStackTrace ();} gqKC4'G0
catch(Exception e){e.printStackTrace ();} 7~QwlU3n<F
zcbA)
U*c{:K-C
Utility.log(nFileLength); jFK9?cLT
+K @J*W 1
E}E7VQjM
return nFileLength; u^;sx/
} %6vMpB`g
P<g|y4h
_~(MA-l
//保存下载信息（文件指针位置） kY0g}o'<
private void write_nPos() y^vfgP<@
{ S<)RVm,!e
try{ $]`'Mi
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6-Vl#Lyb
output.writeInt(nStartPos.length); Ra*k
for(int i=0;i<nStartPos.length;i++) S@l a.0HDA
{ %u<&^8EL+#
// output.writeLong(nPos); ueS[sN!
output.writeLong(fileSplitterFetch.nStartPos); U{.+*e18
output.writeLong(fileSplitterFetch.nEndPos); '{1W)X
} ;FIMCJS
output.close(); FlM.Du
} ?`BED6$`G9
catch(IOException e){e.printStackTrace ();} 3w6JV+?
catch(Exception e){e.printStackTrace ();} pU\xzLD
} zS>:7eG
xw/h~:NT
UOOR0$4
//读取保存的下载信息（文件指针位置） +5seT}h
private void read_nPos() MWp\D#H
{ Mf,Mcvs
try{ h1D~AgZOVj
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *]DJAF]
int nCount = input.readInt(); XJV3oj
nStartPos = new long[nCount]; 2Q;Y@%G
nEndPos = new long[nCount]; Bwi[qw
for(int i=0;i<nStartPos.length;i++) (urfaZ;@+
{ cnjj) c
nStartPos = input.readLong(); RF\1.HJG
nEndPos = input.readLong(); oVxV,oH(
} tkUW)ScJ
input.close(); y}H*p
} Y+Q,4s
catch(IOException e){e.printStackTrace ();} ~,3v<A[5Vi
catch(Exception e){e.printStackTrace ();} a#~Z5>{
} y("0Xve
n?KS]ar>
M<|~MR
private void processErrorCode(int nErrorCode) 1\7"I-
{ \!4ghev3
System.err.println("Error Code : " + nErrorCode); ?yd(er<_f
} 9_CA5?y$:
4<K ,w{I
LMhY"/hAXa
//停止文件下载 #uDBF
public void siteStop() D;T r
{ FZ'>LZ
bStop = true; PY3Vu]zD
for(int i=0;i<nStartPos.length;i++) yvH#1F`{q
fileSplitterFetch.splitterStop(); %<#$:Qb.
sD8xH
sou$qKoG01
} \?`d=n=
} ,BN}H-W\2
//负责部分文件的抓取 t&?v9n"X
**FileSplitterFetch.java C">=2OO
*/ =-B3vd:LF
package NetFox; Ot:\h
]mGsNQ ].H
'c+qBSDA
import java.io.*; XC8z|A-@
import java.net.*; 9gIJX?
}C2i#;b
ne%OTr4dD
public class FileSplitterFetch extends Thread { >c'_xa?^G
\~1zAiSd>#
KLv
String sURL; //File URL 3B_} :
long nStartPos; //File Snippet Start Position A?Hjz%EcW
long nEndPos; //File Snippet End Position Wx\"wlJ7.3
int nThreadID; //Thread's ID p2_Zsq
boolean bDownOver = false; //Downing is over 4~D>oNx4
boolean bStop = false; //Stop identical ?jM7C}
FileAccessI fileAccessI = null; //File Access interface <t|9`l_XW
1V9X(uP
2b&;Y/z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F~- S3p
{ e4_aKuA
this.sURL = sURL; W3-Rs&se
this.nStartPos = nStart; SJuf`
this.nEndPos = nEnd; Pc-8L]2oaF
nThreadID = id; :DF4g=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7!840 :a?+
} D8Waf
E*b[.vUp
D;8V{Hs
public void run() rM?Dp2
{ ,/?V+3l
while(nStartPos < nEndPos && !bStop) %TggNU,
{ }oxaB9r
";Xbr;N
?b''
try{ h.+&=s!Nsy
URL url = new URL(sURL); u0H`%m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^~IcQ!j/5
httpConnection.setRequestProperty("User-Agent","NetFox"); E@}j}/%'O
String sProperty = "bytes="+nStartPos+"-"; _!g NF=
httpConnection.setRequestProperty("RANGE",sProperty); <TROs!x$a
Utility.log(sProperty); WBIB'2:m
H;!hp0y
f*&JfP
InputStream input = httpConnection.getInputStream(); Fea\ eB
//logResponseHead(httpConnection); Jn[ K0GV
$5AtI$TV_!
5pyvs;As
byte[] b = new byte[1024]; <T% hfW
int nRead; uV:uXQni``
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7[<sl35
{ &,kB7r"
nStartPos += fileAccessI.write(b,0,nRead); 8ch~UBq/
//if(nThreadID == 1) `1v!sSR0R
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $YQ&\[pDA
} O]LuL&=s y
ZV^J5wYE
Fmle|
Utility.log("Thread " + nThreadID + " is over!"); MifgRUe
bDownOver = true; HNyDWD)_
//nPos = fileAccessI.write (b,0,nRead); >2{HH\
} +rw3.d
catch(Exception e){e.printStackTrace ();} `Qk R
} !eoec2h#5
} v#2qwd3x
q9(}wvtr
!3v"7l{LF
//打印回应的头信息 d<m>H$\Dm
public void logResponseHead(HttpURLConnection con) tU2;Wb!Y
{ F"TI9ib
for(int i=1;;i++) C`<} nx1
{ {:8[Mdf
String header=con.getHeaderFieldKey(i); TUn@b11
if(header!=null) ")gCA:1-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $^aXVy5p
Utility.log(header+" : "+con.getHeaderField(header)); Q+M3Pqy
else w%-!dbmb%
break; )g<qEyJR
} Y9ce"*b
} sO-R+G/^7
3n)iTSU3
%,q#f#
public void splitterStop() Cx'=2Y7
{ ur[bh
bStop = true; H)fo4N4ii
} fy4JW,c
bUB6B
rAdcMFW
} 7B2Og{P
iDxgAV f*
a~EEow;A
/* VQ3&
**FileAccess.java o=2`N2AL
*//文件访问(定位，写) HUI!IOh
package NetFox; ZKTBjOa]*
import java.io.*; Y }d>%i+
/7)G"qG~F~
7+-}8&syu
public class FileAccessI implements Serializable{ m:7bynT{
oh~Dbu=%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]F-6KeBc
RandomAccessFile oSavedFile; 9'aR-tFun;
long nPos; En_8H[<%
Z|wDM^Lf
IT33E%G
public FileAccessI() throws IOException NU*6iLIq|F
{ "t`e68{Ls
this("",0); u[qtuM?&
} 0evZg@JP`
@h8~xs~DG
lv&wp@
public FileAccessI(String sName,long nPos) throws IOException @"2-tn@q_
{ 99-\cQv
oSavedFile = new RandomAccessFile(sName,"rw"); 9K(b Z{
this.nPos = nPos; ]`m5!V_Y
oSavedFile.seek(nPos); h*%1Jkxu
} k_`S[
50`r}s}
cIkLdh
public synchronized int write(byte[] b,int nStart,int nLen) j* ?MFvwE
{ svgi!=
int n = -1; qeGOSGc_
try{ ~epkRO="
oSavedFile.write(b,nStart,nLen); gI{F"7fa=
n = nLen; `-2`UGB-
} zg"ZXZ
catch(IOException e) akwVU\RP
{ ArMe[t0$
e.printStackTrace (); GMI>$$<
} a$A S?`L
t|_g O!w8
q[g^[~WM#
return n; `Y9@?s Q
} D=]P9XDvb.
|.yRo_
2US8<sq+
} K~G^jAk+
0\A[a4crj
s5@^g8(+C
/* W;W\L? r
**SiteInfoBean.java !;oBvE7Kh
*/ \t3i9#Q
package NetFox; GM~jR-FZ
::w%rv
kY&j~R[C
public class SiteInfoBean { C%h_!z":
<#i'3TUR
F"I@=R-n
private String sSiteURL; //Site's URL Jr zU-g
private String sFilePath; //Saved File's Path rv>6k:(
private String sFileName; //Saved File's Name :PJjy6,1
private int nSplitter; //Count of Splited Downloading File 3f x!\
6A<aelE*i
~C3-E %h@Z
public SiteInfoBean() K[Kc'6G
{//nSplitter的缺省值为5 |H49FL
//default value of nSplitter is 5 $TiAJ}:
this("","","",5); ,P]{*uqGiB
} u)ItML
Wit1WI;18
Pc-HQU
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C_o.d~xm
{ HH+XEMP/g
sSiteURL= sURL; r\?*?sL
sFilePath = sPath; ~$<@:z{*
sFileName = sName; pK%'S
this.nSplitter = nSpiltter; R8_qZ;t:z
!+U.)u9 '
na>B{6
} YjT #^AH
>"b"K{t
O4{&B@!
public String getSSiteURL() O1PdM52
{ "wc $'7M
return sSiteURL; 7O j9~3o4
} z;)% i f6
pw8'+FX
a?dM8zAnc
public void setSSiteURL(String value) LBzpaLd
{ X^`ld&^*({
sSiteURL = value; K7U<~f$OiN
} qW9|&GuZ$
6Z 7$ZQ~
v~SN2,h
public String getSFilePath() . x$` i
{ Iq9+
return sFilePath; +4 dHaj6
} 1'iRx,
o3yZCz
7u;B[qH
public void setSFilePath(String value) #HML=qK~
{ ;Ti?(n#M>
sFilePath = value; QLn5:&
} K4~dEZ
Sq,x@
dbR4%;<
public String getSFileName() 6BMn7m?
{ am=56J$ig
return sFileName; DN+iS
} p<YO3@B+
tSjK=1"}
F+X3CB,f
public void setSFileName(String value) QJ QQ-
{ >2ct1_
sFileName = value; 5:6mptn>
} QP'* )gjO7
(NP=5lLH
W'[!4RQL
public int getNSplitter() VYOO8MQI
{ y]k`}&-~
return nSplitter; '7$v@Tvnre
} 3WhJ,~o-y
DwI)?a_+
6*%lnd+_
public void setNSplitter(int nCount) qsLsyi|zG
{ WH!<Z=#c}
nSplitter = nCount; kG E|17I
} h<uQ~CQg
} BJvVZl2h
UV=TU=A\o
ls=<c<
/* 1i{B47|
**Utility.java &]5<^?3
*/ :geXplTx
package NetFox; d(&vIjy
T]+*}C
6;VlX,,j
public class Utility { YWTo]DJV
McfSB(59
/g21.*Z
public Utility() 3.>jagu
{ zMDR1/|D
tW(E\#!|p<
Z"P{/~HG
} cq/)Yff@:
v<O\ l~S
//线程睡眠 <ioX|.7ZX
public static void sleep(int nSecond) &#WTXTr0=
{ n_5g:`Y
try{ tZ(Wh
Thread.sleep(nSecond); /(Y\ <
} Bk8U\Ut
catch(Exception e) *H;&hq
{ >$}nKPC,Y
e.printStackTrace (); Z:'2puU+?
} d(k`Yk8
} i+2J\.~U#G
y};qo'dlt
//日志 9,,1\0-T*
public static void log(String sMsg) OuX/BMG
{ 'oo]oeJ-
System.err.println(sMsg); Cu>pql<O
} k(Ow.nkb
-"<eq0
;e-iiC]PI
public static void log(int sMsg) L%fWa2P'
{ NvYgRf}uh
System.err.println(sMsg); ,TL~];J'
} %$b 5&>q
} D0uf=BbS
&:Q""e!
1cUC>_%?
/* |%$d/<<PZ
**TestMethod.java l*h6JgU
*/ A+?n=IHh
package NetFox; O'(qeN<^w
f3nib8B'
i2y?CI
public class TestMethod { w+}KX><r
_,vJ0{*
5"{wnnY%K}
public TestMethod() 9)wjVk
{ ///xx/weblogic60b2_win.exe kQ|}"Tw7
try{ |s|RJA1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X~lOFH;}q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); sW[42A
SiteFileFetch fileFetch = new SiteFileFetch(bean); i3YAK$w;&
fileFetch.start(); X!r!lW
} =#8J9
catch(Exception e){e.printStackTrace ();} S&|$F2M
$U!w#|&
wjpkh~qo
} <OpiD%Ctx
u K 8r
.2OP>:9F
public static void main(String[] args) 0(teplo&P
{ OS,-dG(
new TestMethod(); nQ8EV>j2
} G$ipWi
} )5&Wt@7Kj`
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