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)); 99F>n[5
} 4@DVc7\x$
for(int i=0;i<nEndPos.length-1;i++) X$Q2m{dR
{ B;eW/#`
nEndPos = nStartPos[i+1]; x8 f6,
} RRx`}E9,
nEndPos[nEndPos.length-1] = nFileLength; #mgA/q?A
} KU+( YF$1
} d@-wi%,^
YO)')&
LIr(mB"Y0
//启动子线程 R]CZw;zS_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3hc#FmLr2b
for(int i=0;i<nStartPos.length;i++) `6rrXU6|
{ .r~'(g{qt
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TT|-aS0l(u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), UUl*f!& o
nStartPos,nEndPos,i); jEZ "
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &nQRa?3,
fileSplitterFetch.start(); mYjf5
} 5\VxXiy0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %z1{Kus
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); z8b _ _%Br
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +``>,O6
nEndPos = " + nFileLength); q z=yMIy=
// fileSplitterFetch[nPos.length-1].start(); b![t6-f^z
"\`>2
"VV914*z
//等待子线程结束 j,}4TDWa
//int count = 0; [FB&4>V/
//是否结束while循环 !\aV0,
boolean breakWhile = false; rwoF}}
q1UBKhpnH
--Oprl
while(!bStop) c+1vqbqHG
{ LlU'_}>
write_nPos(); '#H&:Htm;L
Utility.sleep(500); {b(rm,%
breakWhile = true; ?LM:RADCm
h>dxBN
]yo_wGiwY
for(int i=0;i<nStartPos.length;i++) fb/qoZ
{ aJI>FTdK
if(!fileSplitterFetch.bDownOver) l x7Kw%
{ h:f;mn?x
breakWhile = false; FnY$)o;
break; ?3[tJreVj
} pXssh
} {&uT3*V1
if(breakWhile) 9 >%+bA(
break; \ZqK\=
}gCG&7C
U%L -NMe
//count++; vsH3{:&;"P
//if(count>4) [4Y[?)7
// siteStop(); n9DbiL1{
} ~+<<bzY
g+.0c=G(
T\jAk+$Jo
System.err.println("文件下载结束！"); mIRAS"Q!m
} C}9Kx }q
catch(Exception e){e.printStackTrace ();} .U<F6I:<md
} C]/&vh7ta
6zuze0ud
k'x#t(
//获得文件长度 D 0
public long getFileSize() HQl~Dh0DJ
{ I:nI6gF
int nFileLength = -1; WI6(#8^p
try{ >ZX|4U[$P
URL url = new URL(siteInfoBean.getSSiteURL()); jSB'>m]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1ADv?+j)A/
httpConnection.setRequestProperty("User-Agent","NetFox"); ^L ]B5,}-
N^lAG"Jao[
wajZqC2yg
int responseCode=httpConnection.getResponseCode(); 4x(F&0
if(responseCode>=400) bhn5Lz$z
{ o,J^ e_
processErrorCode(responseCode); {(%~i37
return -2; //-2 represent access is error !\ZcOk2
} ( :iPm<
J=@xAVBc
|f<9miNu
String sHeader; V7BsEw
B7|c`7x(
S4)A6z$
for(int i=1;;i++) kAeNQRjR
{ KYf;_C,$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fL2^\dB;
//Utility.log(in.readLine()); !f`5B( @
sHeader=httpConnection.getHeaderFieldKey(i); [$;,Ua-mt
if(sHeader!=null) W=3? x
{ V;k#})_-
if(sHeader.equals("Content-Length")) l**3%cTb
{ P0)AUi
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0TmZ*?3!4
break; hD*(AJ
} &5d\~{;
} /w0w*nH
else {gw[%[ZM
break; pD[pTMG@$
} QhsVIta
} }YRO'Q{
catch(IOException e){e.printStackTrace ();} hox< vr4
catch(Exception e){e.printStackTrace ();} j-QGOuvW
lM$t!2pRB
>%l:Dw\A:
Utility.log(nFileLength); 9ZhDZ~)p,
gX_SKy
]hL:33
return nFileLength; a}dw9wU!:
} js -2"I
[<Q4U{F
?;_O 9
//保存下载信息（文件指针位置） >C*4_J7
private void write_nPos() nSHNis
{ lA]N04 d
try{ _CL{IY
output = new DataOutputStream(new FileOutputStream(tmpFile)); m d_g}N(C
output.writeInt(nStartPos.length); me:iQ.g
for(int i=0;i<nStartPos.length;i++) \+9;!VWhl
{ JL``iA
// output.writeLong(nPos); c@9##DPn
output.writeLong(fileSplitterFetch.nStartPos); Ok,HD7
output.writeLong(fileSplitterFetch.nEndPos); n>S2}y
} bM^7g
output.close(); >x*)GPDa
} FllX za)
catch(IOException e){e.printStackTrace ();} `6}Yqh))
catch(Exception e){e.printStackTrace ();} 5#2jq<D
} >MPa38
*{4 ETr7
bJPJ.+G7
//读取保存的下载信息（文件指针位置） 6#vI;d[^
private void read_nPos() ` jyKCm.$#
{ &//2eL
try{ ;t!9]1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >8(jW
int nCount = input.readInt(); 'B,KFA<
nStartPos = new long[nCount]; {"t5\U6cKM
nEndPos = new long[nCount]; \FXp*FbQ
for(int i=0;i<nStartPos.length;i++) ~?d>fR:X
{ ;Yv14{T!
nStartPos = input.readLong(); >uHb ^
nEndPos = input.readLong(); {!r#f(?uT
} _ ~[M+IO
input.close(); 1fRP1
} )(]Envb?A0
catch(IOException e){e.printStackTrace ();} `,P >mp)uU
catch(Exception e){e.printStackTrace ();} N8QH*FX/F1
} TaWaHf
d#8e~
.:N:pWe
private void processErrorCode(int nErrorCode) FB_NkXR
{ dXK-&Po'
System.err.println("Error Code : " + nErrorCode); ^7^2D2[
} j76%UG\Ga
K[]K53Nk
v^TkDf(Oz
//停止文件下载 e[8UH=`|
public void siteStop() 1yS&~ y?a
{ V)h y0_
bStop = true; ~ aA;<#
for(int i=0;i<nStartPos.length;i++) t#~XLCE
fileSplitterFetch.splitterStop(); _*n)mlLln
7@3sUA_Go
B!uxs
} ^cn@?k((A
} #a'r_K=ch)
//负责部分文件的抓取 sG1BNb_
**FileSplitterFetch.java ST% T =_q
*/ s??czM2O
package NetFox; yV2e5/i
wASX\D }
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import java.io.*; gyFr"9';c
import java.net.*; \Z'/+}^h
shzG Eb
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public class FileSplitterFetch extends Thread { #j.FJFGX
#R<G,"N5
b5S7{"<V
String sURL; //File URL mLaCkn
long nStartPos; //File Snippet Start Position P63 (^R
long nEndPos; //File Snippet End Position %qi%$
int nThreadID; //Thread's ID '$6PTa
boolean bDownOver = false; //Downing is over S(tEwXy
boolean bStop = false; //Stop identical R"{l[9j4>
FileAccessI fileAccessI = null; //File Access interface `I#`:hj
lRH0)5`
aaT5u14%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,5. <oDH
{ |*fNH(8&H
this.sURL = sURL; ,Z5Fea
this.nStartPos = nStart; cd&B?\I
this.nEndPos = nEnd; Fs)
nThreadID = id; qRl/Sl#F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4m\([EO
} {$|/|*
I=5dYq4 l
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public void run() PkO!'X
{ ])UwC-l
while(nStartPos < nEndPos && !bStop) I*(1.%:m
{ H`gb}?9R
J `x}{K
3Y(9\}E@`
try{ ofK='G.
URL url = new URL(sURL); hLo>R'@uN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T]uKH29.%
httpConnection.setRequestProperty("User-Agent","NetFox"); `-u7 I
String sProperty = "bytes="+nStartPos+"-"; :*cHA
httpConnection.setRequestProperty("RANGE",sProperty); ThiN9! Y
Utility.log(sProperty); Oq}ip
Ck@M<(x
^9=4iXd
InputStream input = httpConnection.getInputStream(); om>VQ3
//logResponseHead(httpConnection); Ko+al{2
Q0WY$w1<
x G^f
byte[] b = new byte[1024]; zQ<88E&&Xs
int nRead; :P,2K5]y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }PmTR4F!}
{ o X@nP?\
nStartPos += fileAccessI.write(b,0,nRead); N3Z@cp
//if(nThreadID == 1) yf?W^{^|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qCQu^S' iD
} I{EIHD<
?b"Vj+1:x
m/{Y]D{2
Utility.log("Thread " + nThreadID + " is over!"); ,ex]$fQ'
bDownOver = true; 1J&#&\,f&
//nPos = fileAccessI.write (b,0,nRead); BCBUb
} #fN/LO
catch(Exception e){e.printStackTrace ();} L^)qe^%3
} C/
} zhjJ>d%w
zWtj|%ts
9cz)f\
//打印回应的头信息 zuMO1s
public void logResponseHead(HttpURLConnection con) @.1Qs`pt
{ E[ 0Sst x
for(int i=1;;i++) _jo$)x+'x
{ oSmjs
String header=con.getHeaderFieldKey(i); Yw1Y-M
if(header!=null) @7-D7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); WAv@F[
Utility.log(header+" : "+con.getHeaderField(header)); ?Nu#]u-
else NZfd_? 3
break; yi|:}K$
} s&0*'^'O[S
} j3LNnZY
0R*}QXph
NN11}E6
public void splitterStop() :v#8O~
{ ey*,StT5a
bStop = true; 77tZp @>hn
} ]`K[W&
j C9<hLt
%]!?{U\*k
} ExQ--!AC=
w~]}acP
F=:c5z
/* Txu>/1N,
**FileAccess.java `BpCRKTG
*//文件访问(定位，写) RW)k_#%=
package NetFox; &*jixqzvn
import java.io.*; HwM/}-t
c[Yq5Bu{y
}-dF+m:
public class FileAccessI implements Serializable{ v|>BDN@,6
tpE3|5dZF
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =uS8>.Qj
RandomAccessFile oSavedFile; TtZrttCE6
long nPos; Rn8#0%/Q
^>eFm8`N
Nl=+.d6Qo
public FileAccessI() throws IOException +yvBSpY
{ yG4MUf6
this("",0); F; 0Dp
} #|q;t
X!m;uJZp
oR77`
public FileAccessI(String sName,long nPos) throws IOException u$\Tg3du2
{ ~O8]3+U
oSavedFile = new RandomAccessFile(sName,"rw"); >H8^0n)?
this.nPos = nPos; |]I#CdO
oSavedFile.seek(nPos); _4O[[~
} ,I=O"z>9
6mX:=Q
8XgVY9]Qm
public synchronized int write(byte[] b,int nStart,int nLen) eMztjN
{ /1U,+g^O>
int n = -1; aQC7V!v
try{ E|\3f(aF
oSavedFile.write(b,nStart,nLen); K:C+/O
n = nLen; Kgps_tY%
} D=<t;+|
catch(IOException e) - f+CyhR"*
{ k#BU7Exij
e.printStackTrace (); uLF\K+cz
} 3$;J0{&[i
N c9<X
Ogn,1nm%
return n; oK%K+h
} #xDDh`
^BQ>vI'.4
zv>ZrFl*
} Z5 w`-#
nvw NjN
L>eQ*311
/* I):m6y@
**SiteInfoBean.java Z(#XFXd
*/ 34HFrMi
package NetFox; X}kVBT1w+x
s#M? tyhj
'Wd3`4V$
public class SiteInfoBean { ikeJDKSG
@?(nwj~ s`
+ ?[ ACZF
private String sSiteURL; //Site's URL QJb7U5:B+
private String sFilePath; //Saved File's Path @DRfNJ}
private String sFileName; //Saved File's Name \3,$YlG
private int nSplitter; //Count of Splited Downloading File %jYQ
8.6no
9N`+ O
public SiteInfoBean() yN%3w0v
{//nSplitter的缺省值为5 }mkA Hmu4
//default value of nSplitter is 5 q=(M!9cE
this("","","",5); t"jIfU>'a/
} o%y+Y;|?J
bL6L-S
ufHuI*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6yV5Yjs
{ =P@M&Yy'
sSiteURL= sURL; ;))[P_$zB
sFilePath = sPath; :T8u?@.
sFileName = sName; hlYS=cgY=
this.nSplitter = nSpiltter; Ih9ORp7
rcD.P?"
eA;j/&qH
} iPR!JX _
zzDNWPzsA
e)fJd*P
public String getSSiteURL() A?%XO %
{ TW;|G'}$
return sSiteURL; *rujdQf
} $_%2D3-;D
'US8"83
)of5229
public void setSSiteURL(String value) eHfG;NsV/
{ *RUd!]bh
sSiteURL = value; VuYWb)@
} ^H@!)+ =
oi%5t)VsS
0%(4G83gw
public String getSFilePath() 81%qM7v9H
{ WHdqO8
return sFilePath; j};pv2
} >vNk kxWyQ
8VBkIYgb
v)v{QNQp^
public void setSFilePath(String value) a!SR"3 k
{ KBUAdpU8
sFilePath = value; 83p$!8]u
} 0e7O#-
h;:Se
g(z#h$@S
public String getSFileName() ^"6D0!'N
{ 7k[`]:*o
return sFileName; =]2RC1#}e
} MfZ}xu
8H$@Xts
N'Z_6A*-
public void setSFileName(String value) umHs"d
{ <7sF<KD
sFileName = value; |{}d5Z"5;}
} ?$`1%Y9
KqG$zC^N
` i^`Q
public int getNSplitter() c=jTs+h'
{ *n$m;yI
return nSplitter; z!Pdivx
} }hObtAS
(pRy1DH~
Rzn0-cG
public void setNSplitter(int nCount) F?+Uar|-a
{ |tolgdj
nSplitter = nCount; J T0,Z
} !@]h@MC$7
} JVIcNK)
Nsy9 h}+A
^0,&R\e+
/* G+\~rl
**Utility.java .-1{,o/&Q
*/ 5D02%U2N)G
package NetFox; .ON$vn7
KzFs#rhpn
V }r_
public class Utility { UU:QK{{E
0I ND9h.%
Z:o' +oh
public Utility() v'2OHb#
{ Kw5+4R(5
bju,p"J1-E
+XaO?F[c
} ]aMa*fF
~]t2?SqNm
//线程睡眠 yI)RGOV
public static void sleep(int nSecond) (/rIodHJO
{ 3 v,ae7$U&
try{ F" #3s=
Thread.sleep(nSecond); ju2X*
} L^ jC& dF
catch(Exception e) YQ[&h
{ SJ|.% gn
e.printStackTrace (); 5IF~]5s
} BX)cV
} W~@GK
M$-(4 0
//日志 yKk,);
public static void log(String sMsg) G4`sRaT.
{ p=P0$P+KM
System.err.println(sMsg); iRr&'k
} M6>\R$
/-<m(72wF
n*8RYm)?
public static void log(int sMsg) 1_E3DXe
{ :92a34
System.err.println(sMsg); J;]@?(
} NB6h/0*v
} #L*@~M^]
%cjGeS6}
KL_}:O68
/* /n3&e
**TestMethod.java V/[,1W[B
*/ B[m{2XzGH
package NetFox; )^'B:ic
moM&2rgdrQ
e^fKatI1
public class TestMethod { $A!h=]
v(nQd6;T
(R 2P< Zr
public TestMethod() R"kE5:
{ ///xx/weblogic60b2_win.exe Chi<)P$^
try{ 1Qe!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~X(xa
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N)I T?
SiteFileFetch fileFetch = new SiteFileFetch(bean); PHL@1K{)
fileFetch.start(); CzsY=DBH=
} Dp |FyP_w
catch(Exception e){e.printStackTrace ();} Q1&dB{L
B+H9c~3$
rls#gw
} qA\kx#v]P
'!L1z45
ob5nk^y
public static void main(String[] args) I!0+RP(
{ G78j$ ^/0
new TestMethod(); %_=R&m'n`
} U=#ylQ
} Z1lF[d,f;
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