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)); unE h
} i:ar{ q
for(int i=0;i<nEndPos.length-1;i++) :W'Yt9v)
{ J23Tst#s
nEndPos = nStartPos[i+1]; >;@ _TAF
} bn`1JI@S4
nEndPos[nEndPos.length-1] = nFileLength; D&5>Op4U
} 1mT3$Z
} F,2)Udim
C'bW3la
YGp8./ma<I
//启动子线程 Uloa]X=Im8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; //C3tW
for(int i=0;i<nStartPos.length;i++) Wj2s+L7,
{ F@e9Dz|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I@dS/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), nic7RN?F<
nStartPos,nEndPos,i); ka_]s:>+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gXtyl]K:
fileSplitterFetch.start(); Q+e|;Mj
} plL##?<D<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RS&l68[6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g'G"`)~ 2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?-^eI!
nEndPos = " + nFileLength); FJ}RT*7_C
// fileSplitterFetch[nPos.length-1].start(); sQt]Y&_/@
b&k !DeE
&A=>x
//等待子线程结束 i7h!,vaK
//int count = 0; 6FMW}*6<
//是否结束while循环 x!CCSM;q
boolean breakWhile = false; ?yKW^,q+
_yje"
Y8I*B=7
while(!bStop) NABwtx>.
{ ?C#=Q6
write_nPos(); _jmkAmeu
Utility.sleep(500); ?m3,e&pB5
breakWhile = true; xA|72!zk0P
Fl,(KSTz
c}9.Or`?
for(int i=0;i<nStartPos.length;i++) YGVj$\
{ NP%Y\%;l6
if(!fileSplitterFetch.bDownOver) |G.|ocj;
{ BElVkb
breakWhile = false; CB(Qy9C%h[
break; 02Z>#AE
} 2/.Euf
} n6T@A;_g
if(breakWhile) iU^KmM I
break; DgOO\
h+o-h4X
s53Pw>f
//count++; h WvQh
//if(count>4) `usX(snY
// siteStop(); 1#H=<iJ
} *QAcp` ;*
,v;P@RL|g
6 /8?:
System.err.println("文件下载结束！"); E?> ERO3
} W79wz\a
catch(Exception e){e.printStackTrace ();} 7hPiPv
} > %5<fK2
+o]DT7W
-3 .Sr|t
//获得文件长度 -eH5s3:A
public long getFileSize() \W5fcxf
{ .Y}~2n
int nFileLength = -1; *g =ey?1S
try{ 0pT?qsM2
URL url = new URL(siteInfoBean.getSSiteURL()); ^J,Zl`N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Kj|l]'
httpConnection.setRequestProperty("User-Agent","NetFox"); g9 .b6}w!
OQt_nb#z`{
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int responseCode=httpConnection.getResponseCode(); P !:LAb(
if(responseCode>=400) xij`Mr
{ =FXO1UZ!
processErrorCode(responseCode); =b{wzx}e
return -2; //-2 represent access is error P@Oq'y[
} i v7^!
ay}}v7)GM
=<ngtN
String sHeader; x9UF
+Tnn'^4
Gh3b*O_,
for(int i=1;;i++) d>j`|(\
{ :q_(=EA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); eH.~c3o
//Utility.log(in.readLine()); 9sQ7wlK
sHeader=httpConnection.getHeaderFieldKey(i); {DzOXTI[Y
if(sHeader!=null) BeAkG_uG
{ y7ng/vqM7
if(sHeader.equals("Content-Length")) ZzZy2.7
{ `9IG//
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N?]HWP^pg
break; 4[=vt
} e nsou!l
} ,,_$r7H`
else r+6=b"
break; B%Pg:|
} I<p- o/TP
} Z(F`M;1>xI
catch(IOException e){e.printStackTrace ();} JHN{vB
catch(Exception e){e.printStackTrace ();} XcfvmlBoD-
8G&'ED_&
nksx|i l
Utility.log(nFileLength); {OA2';3
~\;s}Fv.
JDi\?m d.
return nFileLength; L\1&$|?
} u-yVc*<,
R(jp
b^WTX
//保存下载信息（文件指针位置） Bf {h\>q
private void write_nPos() q~QB?+ x&
{ xaQO=[
try{ 0E[&:6#Y
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3aL8GMiu
output.writeInt(nStartPos.length); >)E{Hs
for(int i=0;i<nStartPos.length;i++) Npq_1L
{ Aj9<4N
// output.writeLong(nPos); KxZup\\:v
output.writeLong(fileSplitterFetch.nStartPos); hzG+s#
output.writeLong(fileSplitterFetch.nEndPos); >NL4&MV:
} $\:;N]Cs~0
output.close(); N@Fof(T&
} CKoRq|QG_
catch(IOException e){e.printStackTrace ();} L[M`LZpJo
catch(Exception e){e.printStackTrace ();} Rd|#-7
} KmUH([#
2y"]rUS`
;8!L*uMI
//读取保存的下载信息（文件指针位置） (yh zjN~
private void read_nPos() g9N_s,3jC
{ oT=XCa5
try{ x6-bAf
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~!bA<q
int nCount = input.readInt(); :PJ5~7C
nStartPos = new long[nCount]; a#Yo^"*1
nEndPos = new long[nCount]; 1?6zsA%N
for(int i=0;i<nStartPos.length;i++) &w4~0J>v!
{ bq+Q$#F2X
nStartPos = input.readLong(); V4~`yT?*"
nEndPos = input.readLong(); gaBVD*>
} .(D,CGtYb
input.close(); S3cV^CzNg
} HN7C+e4U~
catch(IOException e){e.printStackTrace ();} X:3W9`s)*
catch(Exception e){e.printStackTrace ();} >ZX&2 {
} 2h:*lV^
WoYXXYP/E
>)V1aLu=
private void processErrorCode(int nErrorCode) aJAQ G
{ sr|afqjXD
System.err.println("Error Code : " + nErrorCode); 2D`_!OG=
} j,:vK
B)^uGSW
-pb>=@Yq
//停止文件下载 )I/K-zj
public void siteStop() \%=GM J^[p
{ y5oC|v7
bStop = true; B<et&r;
for(int i=0;i<nStartPos.length;i++) $7\!
fileSplitterFetch.splitterStop(); |3ob1/)p0
*3A`7usU
BH@b]bEJ
} Hu4\4x$?
} oQsls9t
//负责部分文件的抓取 'h]sq{
**FileSplitterFetch.java at(oepq
*/ ;s$bVGHr
package NetFox; 9/LnO'&-
-FxE!K
JZc"4qf@OT
import java.io.*; R:[IH2F s
import java.net.*; KUR9vo
-c_}^j
xzI?'?duC
public class FileSplitterFetch extends Thread { klUW_d-
_T8o]
dE ,NG)MH
String sURL; //File URL VZo,AP~
long nStartPos; //File Snippet Start Position U/p|X)
long nEndPos; //File Snippet End Position ke~S[bL%-
int nThreadID; //Thread's ID # Vq"Cf
boolean bDownOver = false; //Downing is over o?T01t=
boolean bStop = false; //Stop identical z8n=\xL
FileAccessI fileAccessI = null; //File Access interface E;*JD x
4/_@F>I_
M2{AaYgD
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]&oQ6
{ DrY5Q&S
this.sURL = sURL; 2%i3[N*
this.nStartPos = nStart; ,o?yS>L_r
this.nEndPos = nEnd; =x QLf4>
nThreadID = id; \R}`S`fIw`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 rhr(uCp/
} v \xuq`
x!@3.$
B#Q=Fo 6
public void run() Lt<KRs
{ XFS"~{
while(nStartPos < nEndPos && !bStop) <E&[sQ|3
{ ~WKcO&
94Hs.S)
"{1SDbwmMo
try{ $t1XoL
URL url = new URL(sURL); Z` ;.62S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6Z:swgi6&
httpConnection.setRequestProperty("User-Agent","NetFox"); ue/GB+U
String sProperty = "bytes="+nStartPos+"-"; $$GmundqB
httpConnection.setRequestProperty("RANGE",sProperty); ` 6'dhB
Utility.log(sProperty); 0P%,1M3d
|o5F%1o
VK~ OL
InputStream input = httpConnection.getInputStream(); "&@v[O)!xu
//logResponseHead(httpConnection); &OXnZT3P
)9PP3"I
eG F{.]
byte[] b = new byte[1024]; 0}:wM':G
int nRead; |K7zN\ Wq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }BR@vY'd
{ bAd$ >DI[
nStartPos += fileAccessI.write(b,0,nRead); Ie<`WU K
//if(nThreadID == 1) p%?VW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /&T"w,D
} kr=&x)Wy!
4!3mSWNV
|IgH0 zZ
Utility.log("Thread " + nThreadID + " is over!"); l+V#`S*q
bDownOver = true; h^`!kp
//nPos = fileAccessI.write (b,0,nRead); R, J(]ew
} doj$chy
catch(Exception e){e.printStackTrace ();} >axf_k
} Qgel^"t]i
} X-mhz3Q&a
piy_9nk
;FI"N@z
//打印回应的头信息 kCuIEv@
public void logResponseHead(HttpURLConnection con) <z2*T \B!8
{ #$dk
for(int i=1;;i++) FK:Tni
{ \{Yi7V Xv
String header=con.getHeaderFieldKey(i); .dr-I7&!
if(header!=null) "j]85
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QEb ^'y
Utility.log(header+" : "+con.getHeaderField(header)); O0i)Iu(J7;
else FFvF4]|L
break; QL{^
} B0&W wa:
} /Ayo78Pi
>E:V7Fa
AfV a[{E
public void splitterStop() Pv>W`/*_,s
{ $QbaPmHW
bStop = true; zdh&,!] F6
} "F.0(<4)
YR\pt8(z?
$v#\bqY
} VEtdp*ot
:I)WSXP9h
jH4'jB
/* B7R*g,(
**FileAccess.java Alh"ZT^*
*//文件访问(定位，写) "'8^OZR
package NetFox; [*jvvkAp
import java.io.*; %`F&,!d
N-~Uu6zr
Te:4z@?
public class FileAccessI implements Serializable{ k|-P&g
:K#z~#n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C'a%piX
RandomAccessFile oSavedFile; p3N/"t&>
long nPos; 6')pM&`t
XLeQxp=
L+rMBa
public FileAccessI() throws IOException ZWVN(U
{ gFx2\QV
this("",0); ;YYo^9Lh}
} )uJu.foE
O`pqS\H
T/b%,!N)
public FileAccessI(String sName,long nPos) throws IOException Z%t"~r0PS
{ D^Cpgha
oSavedFile = new RandomAccessFile(sName,"rw"); "G+g(?N]j
this.nPos = nPos; wVw?UN*rm;
oSavedFile.seek(nPos); \TF='@u.
} X`n)]~
v"po}K
Ew9\Y R}
public synchronized int write(byte[] b,int nStart,int nLen) y7?n;3U]CS
{ ioZ{2kK
int n = -1; YKk*QcAn
try{ VPAi[<FzOG
oSavedFile.write(b,nStart,nLen); eMDO;q
n = nLen; 5ml#/kE
} YaWZOuxm
catch(IOException e) ST*\Q
{ #KOr-Yg|U
e.printStackTrace (); LZ?z5U:
} *G6Py,- !f
)fRZ}7k:
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return n; vfn _Nq;
} _3_kvs
L T.u<ThR}
LrL ZlJf
} C1V@\mRi
_(R1En1
p#yq'kY
/* L93PDp4v
**SiteInfoBean.java "Q>gQKgL
*/ LxcC5/@\~(
package NetFox; VD,p<u{r
5Q9nJC{'NN
Tf|?j=f
public class SiteInfoBean { V^
Xqz\%&G
R[%ZyQ_
private String sSiteURL; //Site's URL Ep.Q&(D >
private String sFilePath; //Saved File's Path ~eVq Fc
private String sFileName; //Saved File's Name %+=y!
private int nSplitter; //Count of Splited Downloading File D>Ub)i
$P{|^ou3a#
=.sg$VX
public SiteInfoBean() 2%|0c\y|z=
{//nSplitter的缺省值为5 mHiV};$
//default value of nSplitter is 5 S1!X;PP/
this("","","",5); D<DSK~
} ^~iFG+g5
tz).]E D
8c6dTT4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qir/Sa'[
{ $CXMeY{tOo
sSiteURL= sURL; `[&) X
sFilePath = sPath; 5f` a7R
sFileName = sName; GmONhh(k
this.nSplitter = nSpiltter; #DqVh!t"
+J`HI1
npj_i /&g
} x3`b5^
whA
EGY'a*]cU
public String getSSiteURL() G~ldU: ?
{ 0# )I:5
return sSiteURL; N 9.$--X}D
} ?bq S{KF
-Tzp;o
g?}$"=B
public void setSSiteURL(String value) g}vOp3^
{ 4F-r}Fj3
sSiteURL = value; n)n>|w_
} ?tf/#5t}
em@bxyMm
ZSBa+3;z
public String getSFilePath() w6-A-M6hD
{ iPD5 KsAOA
return sFilePath; B;3lF;3`
} a/nKKhXaM
1feZ`P;
+5zLQ>]z
public void setSFilePath(String value) &EELq"5K
{ Nx%]dOa
sFilePath = value; 8Moe8X#3
} }k`-n32)|
9i&(VzY[=
3!&PI
public String getSFileName() /uh?F
{ rzR=% >
return sFileName; xD:t$~
} dTE(+M- Gr
4P>[]~S
g}cb>'=={
public void setSFileName(String value) k^JV37;bl
{ ??'>kQ4
sFileName = value; v>p UVM
} e%Sw(=a
oCCTRLb02
gB&8TE~Y
public int getNSplitter() (O&R-5m
{ '=M4(h
return nSplitter; jHU5>Gt-}
} )&nfV5@"
b3h3$kIYN
fP:n=A{
public void setNSplitter(int nCount) dGNg[
{ H}nPaw]G
nSplitter = nCount; H*gX90{!2
} ]12ypcf
} >Q`\|m}x)Q
K5h2 ~
2 SJN;A~}
/* XBmAD!
**Utility.java -$x5[6bN
*/ + YjK#
package NetFox; T3JM8
C:?mOM#_
"-WEUz
public class Utility { -MCDX^>P
.# Jusd
1-h"1UN2E
public Utility() eB]R<a60
{ ]"*sp
bg =<)s
k|r+/gIV
} MYmH?A
(59u<F
//线程睡眠 ;b-d2R
public static void sleep(int nSecond) kT=KxS{
{ "u H VX|`
try{ wqZ*$M
Thread.sleep(nSecond); [yEH!7
} ri]"a?Rm
catch(Exception e) d:_3V rRZ
{ G2,9$8qE
e.printStackTrace (); /}ADV2sF
} o)M=; !
} kf Xg\6uKc
}(yX$ 3?`
//日志 ^@4$O|3Wh'
public static void log(String sMsg) G<MX94?
{ ,P T5-9 m
System.err.println(sMsg); v)!C Dpw
} $3BH82
[%1 87dz:D
hE9UWa.Q>
public static void log(int sMsg) G'dN_6ho3
{ T+q3]&
System.err.println(sMsg); E[nJ'h<h
} :mI[fQ
} 'A#bBn,|
fPj*qi
Ibbpy++d[
/* n;w&}g
**TestMethod.java ,5 A&
*/ 50?5xSEM0_
package NetFox; o=}vK[0u
$.g)%#h:
,Qw\w,
public class TestMethod { >~vZ+YO
`+c8;p'q
`;R [*7
public TestMethod() WNa#X]*E)
{ ///xx/weblogic60b2_win.exe (UGmbRf&
try{ p&O-]o8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g:&V9~FR
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); XVRtfo
SiteFileFetch fileFetch = new SiteFileFetch(bean); aP}%&{iC*
fileFetch.start(); F,NS:mE
} pRTdP/(OQ
catch(Exception e){e.printStackTrace ();} F VVpyB|
LL}b]B[
M,WC+")Z=
} {-'S#04
4pw:O^v
.%3qzOrN
public static void main(String[] args) M?FbBJ`sF
{ -AX[vTB
new TestMethod(); jaOt"iU.B
} $(PWN6{\r^
} zB@@Gs>
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