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)); kSW=DE|#}
} Lzr&Q(mL
for(int i=0;i<nEndPos.length-1;i++) F~bDA~
{ *R'r=C`
nEndPos = nStartPos[i+1]; " V[=U13
} >(EC.ke
nEndPos[nEndPos.length-1] = nFileLength; ?<F=*eS
} 6XP>qI,AJ
} "0*yD[2
!sknO53`H`
e>$d*~mwn
//启动子线程 ON(OYXj
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Bb[WtT}=
for(int i=0;i<nStartPos.length;i++) @euH[<
{ %fbV\@jDCX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <K g=?wb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <v=$A]K
nStartPos,nEndPos,i); vl`Qz"Xy
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9f(0 qa
fileSplitterFetch.start(); DB~3(r?K
} .j et0w
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?xa70Pb{;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rt rPRR\:"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %>p[;>jW
nEndPos = " + nFileLength); .2Q4EbM2
// fileSplitterFetch[nPos.length-1].start(); 8=K%7:b
f 7R/i
r|MBkpcvp
//等待子线程结束 %fT%,( w}t
//int count = 0; -R]Iu\
//是否结束while循环 T\ *#9a
boolean breakWhile = false; A ".v+
@d&JtA
kk`K)PESi
while(!bStop) ^l:~r2
{ <<=.;`(/v
write_nPos(); 8AjQPDn+
Utility.sleep(500); ]KQv]'
breakWhile = true; 9T\uOaC"
n1!}d%:
VGYx(
for(int i=0;i<nStartPos.length;i++) 12i<b
{ %nS(>X<B
if(!fileSplitterFetch.bDownOver) eS`ZC!W
{ elqm/u
breakWhile = false; E"O6N.}.
break; AZ9;6Df
} z|F38(%JJN
} > `1K0?_
if(breakWhile) v~*Co}0OB
break; ~xa yGk
70GwTK.{~
=.`:jZG
//count++; U#iGR5&^3
//if(count>4) &ir|2"HV
// siteStop(); sSLVR^
} P5JE = &M
_4f=\
bMA0#e2
System.err.println("文件下载结束！"); b FMBIA|
} <e?1&56
catch(Exception e){e.printStackTrace ();} 4<j7F4
} *V`E)maU
erQQ_
M=M~M$K
//获得文件长度 zv-9z
public long getFileSize() R?3N><oh*
{ 4C#r=Uw`
int nFileLength = -1; eP|_
try{ pJ3-f k"i
URL url = new URL(siteInfoBean.getSSiteURL()); w61*jnvi@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WK.K-bd
httpConnection.setRequestProperty("User-Agent","NetFox"); 2@6Qifxd@
Ueu~803~
N79?s)l:K
int responseCode=httpConnection.getResponseCode(); 3Q#Tut
if(responseCode>=400) h+c9FN
{ i*]$_\yl"
processErrorCode(responseCode); z',f'3+
return -2; //-2 represent access is error xrZzfg
} M?d(-en
Ihd{tmr<
o(gV;>I
String sHeader; Gc=uKQ+\V
o?g9Grk
y&W3CW\:
for(int i=1;;i++) xV0:K=
{ O@>ZYA%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &R))c|>OT&
//Utility.log(in.readLine()); ?{;7\1[4
sHeader=httpConnection.getHeaderFieldKey(i); IkuE|
if(sHeader!=null) X%98k'h.y
{ ?orLc,pU^
if(sHeader.equals("Content-Length")) ^H!45ph?Jc
{ qoP/`Y6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kXgc'w6EhF
break; /,yRn31[
} w.(?O;
} |\U5m6q
else >|pN4FS
break; a0jzt!ci
} #Ibpf ,
} Gn%"B6
catch(IOException e){e.printStackTrace ();} Zg4kO;r08
catch(Exception e){e.printStackTrace ();} $!vK#8-&{
z?Cez*.h>
[VE>{4]W
Utility.log(nFileLength); T<%%f.x[s
7lx]`u>
rhDiIO_
return nFileLength; 3Ct:AJeg
} 6 u1|pX8
G-TD9OgZ
%l3f .
//保存下载信息（文件指针位置） \iA.{,VX
private void write_nPos() 9DmFa5E
{ gh-i|i,
try{ F@b=S0}K
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1'%n?\OK66
output.writeInt(nStartPos.length); $T6+6<
for(int i=0;i<nStartPos.length;i++) )SHB1U25{
{ A!v:W6yiz
// output.writeLong(nPos); =u`tlN5pOT
output.writeLong(fileSplitterFetch.nStartPos); @Hl+]arUh
output.writeLong(fileSplitterFetch.nEndPos); G+t=+T2m
} T|2v1Vj
output.close(); XE8%t=V!c$
} y7Nd3\v [\
catch(IOException e){e.printStackTrace ();} 3*E] :l_
catch(Exception e){e.printStackTrace ();} &W}6Xg(
} cEIs9;
c5Hyja=
6!C>J#T
//读取保存的下载信息（文件指针位置） M0t9`Z9
private void read_nPos() K@vU_x0Sl
{ UZ1Au;(|
try{ -' =?Hs.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >uxAti\
int nCount = input.readInt(); 3i#'osq
nStartPos = new long[nCount]; !ou;yE&<,
nEndPos = new long[nCount]; tC5>K9Ed
for(int i=0;i<nStartPos.length;i++) (W.G&VSn)
{ yUN>mD-
nStartPos = input.readLong(); Y[s}?Xu]w#
nEndPos = input.readLong(); s`|KT&r
} $|N\(}R
input.close(); ?ph>:M
} ovZ!}
catch(IOException e){e.printStackTrace ();} )|GYxG;8C
catch(Exception e){e.printStackTrace ();} }S;A%gYm
} VHG}'r9KC%
qFI19`?8E
?z0W1a
private void processErrorCode(int nErrorCode) yG^pND>_df
{ V}ls|B$Y
System.err.println("Error Code : " + nErrorCode); t)mc~M9w
} }nptmc
QabLMq@n`
[@2$W?0i
//停止文件下载 TUARYJ6=
public void siteStop() m%b#B>J,n
{ !AG {`[b
bStop = true; fVJWW):
for(int i=0;i<nStartPos.length;i++) "8Lv
fileSplitterFetch.splitterStop(); rN,T}M=2
L^=G(op*
&(m01
} Hp*N%
} dl(!{tZ#
//负责部分文件的抓取 6#Rco%07zI
**FileSplitterFetch.java Ph)>;jU
*/ ZFX6iAxd
package NetFox; e>P>DmlW
*-S?bv,T'
TkVqv v
import java.io.*; :%h|i&B
import java.net.*; X6BOB?
j_h0hm]
%/d1x
public class FileSplitterFetch extends Thread { s{*bFA Z1F
^v+p@k
czsnPmNEI
String sURL; //File URL r5y*SoD!
long nStartPos; //File Snippet Start Position DPkH:X
long nEndPos; //File Snippet End Position ,b:~Vpb1I
int nThreadID; //Thread's ID `fE'$2
boolean bDownOver = false; //Downing is over i1K$~
boolean bStop = false; //Stop identical G=LK irj(
FileAccessI fileAccessI = null; //File Access interface lh6N3d
|D_4 iFC
.#Z"Sj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {gxP_>
{ #N;&^El
this.sURL = sURL; h^,av^lg^
this.nStartPos = nStart; ZZ T 9t#~
this.nEndPos = nEnd; ]0g p.R
nThreadID = id; =G !]_d0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^9><qKbO
} |7Qe{
13 %:3W(
!L<z(dV|(
public void run() rs,'vV-2\
{ hZw8*H^tP
while(nStartPos < nEndPos && !bStop) 7* [
{ N( f0,
%j2$ ezud
3#Iq5vT
try{ nFWiS~(#sW
URL url = new URL(sURL); V9Dq<y-y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DS_0p|2
httpConnection.setRequestProperty("User-Agent","NetFox"); "y5bODq3t
String sProperty = "bytes="+nStartPos+"-"; 7-0j8$`
httpConnection.setRequestProperty("RANGE",sProperty); g+7j?vC{'
Utility.log(sProperty); z`p9vlS[
~z,qr09
<AK9HPxP
InputStream input = httpConnection.getInputStream(); .Hk.'>YR
//logResponseHead(httpConnection); i5|)|x3
:i|]iXEI"
O<ybiPR
byte[] b = new byte[1024]; h lSav?V_
int nRead; @(0O9L F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2H`>Kj
{ 3d,:,f|h
nStartPos += fileAccessI.write(b,0,nRead); R}IuMMx
//if(nThreadID == 1) Xq<_r^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FlUO3rc|
} bkz/V/Y
bcT'!:
X<5&R{oZ
Utility.log("Thread " + nThreadID + " is over!"); !R@jbM
bDownOver = true; ,9MNB3
//nPos = fileAccessI.write (b,0,nRead); oS}fr?
} x0K#-
catch(Exception e){e.printStackTrace ();} HKIr?
} Q#*R({)GH
} Z>l<.T"t'
FGhnK'
3sW!ya-VZ
//打印回应的头信息 bnPhhsR
public void logResponseHead(HttpURLConnection con) "{trK?-8%
{ *Vg)E*s
for(int i=1;;i++) eNO[ikm
{ +1@'2w{
String header=con.getHeaderFieldKey(i); ;.b^&h
if(header!=null) &aa3BgxyE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -%Rbd0gVH\
Utility.log(header+" : "+con.getHeaderField(header)); ;}M&fXFp"|
else Z[0/x.pp$
break; 4Xww(5?3
} `m#i|8
} m&z(2yb1
'=eVem=
6{0MprY
public void splitterStop() REh\WgV!u
{ URt+MTU[
bStop = true; /8<c~
} S]Di1E^r;_
U3{4GmrT
YK5(oKFN
} [=tIgMmz
{[hgSVN;
`U|zNizO
/* 0cVxP)J+
**FileAccess.java mIPDF1=)
*//文件访问(定位，写) $RunGaX!=N
package NetFox; j(}pUV B
import java.io.*; WF_QhKW|k
IYHNN
G]{^.5
public class FileAccessI implements Serializable{ |n^rI\p%
.g?D3$|K
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >3~)2)Q
RandomAccessFile oSavedFile; cYXL3)p*Q
long nPos; bUds E1f
] W$V#
?RW1%+[
public FileAccessI() throws IOException DrbjklcUU
{ $o9@ ?2
this("",0); g \ou+M#
} kbJ4CF}H
B6KG\,'|
M*C1QQf\N
public FileAccessI(String sName,long nPos) throws IOException MmePhHf
{ a.RYRq4o
oSavedFile = new RandomAccessFile(sName,"rw"); wp5H|ctl
this.nPos = nPos; dV16'
oSavedFile.seek(nPos); .p?SPR
} qQ6@43TC
-yTIv*y
wh2E$b(-
public synchronized int write(byte[] b,int nStart,int nLen) & JJ*?Dl
{ _ n1:v~
int n = -1; shP}T[<
try{ F2ISg'
oSavedFile.write(b,nStart,nLen); z#rp8-HUDS
n = nLen; ;>;it5 l=
} "Nz@jv?
catch(IOException e) >oaL-01i
{ o^MoU2c
e.printStackTrace (); ZU;jz[}
} F6b;qb6n
wXKt)3dmu
TJ_6:;4,|_
return n; Zb|a\z8?
} {E7STLQ_%
qmenj
LR\8M(rtvH
} pd& HC
R@/"B?`(f
2JcP4!RD
/* 3 `mtc@*
**SiteInfoBean.java >,I'S2_Zl
*/ &\Lu}t7Ru
package NetFox; ZLPj1L
c@)?V>oe
&%8IBT
public class SiteInfoBean { #};Zgixo$
};EB[n
jW-;Y/S
private String sSiteURL; //Site's URL 412E7
private String sFilePath; //Saved File's Path hE$3l+
private String sFileName; //Saved File's Name |JP'j1 Ka
private int nSplitter; //Count of Splited Downloading File fny6`_O
M)AvcZNs
h@\HPYi#.
public SiteInfoBean() ?r5a*
{//nSplitter的缺省值为5 r.6?|
//default value of nSplitter is 5 ,?Zy4-
this("","","",5); ='_3qn.
} i\gt @
79-50}A
+Ar4X-A{y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q^n LC6q
{ 1oQbV`P
sSiteURL= sURL; {6wXDZxv
sFilePath = sPath; (TO<SY3AB
sFileName = sName; W:6#0b"_#
this.nSplitter = nSpiltter; 25 :vc0
n%iL+I
kC6Y?g
} 4FZ/~Y1}
|"9vq<`
i~R+g3oi
public String getSSiteURL() p~""1m01,D
{ Sm?|,C3V
return sSiteURL; 7,V_5M;t
} LU`)
w"#rwV&
%}Y&qT?
public void setSSiteURL(String value) QD%6K=8Q
{ >!{8)ti
sSiteURL = value; aNQ(xiskb
} rKdsVW
k B4Fz
8Gy*BpmJn
public String getSFilePath() 81(\8#./
{ sG[qlzR=8
return sFilePath; aGsO~ODc
} s{V&vRr
8Q{9AoQ3'
w'VuC82SZ
public void setSFilePath(String value) U5@B7v1
{ \u(Gj]B#"
sFilePath = value; v0tFU!Q%
} dLwP7#r
8*&73cp
Gm=&[?}
public String getSFileName() l @@pXg3
{ Qz%q#4Zb
return sFileName; ZrA*MN
} (x.qyYEoI
6Yt3Oq<U
NLYf
public void setSFileName(String value) pS7y3(_
{ 61OlnmvE
sFileName = value; Gl45HyY_
} I,,SR"
aRI.&3-
_5O~]}
public int getNSplitter() %W|Sl
{ :?m"kh ~
return nSplitter; C=U4z|Ym
} 9f5~hBlo
1&7?f
DB_oRr[oj
public void setNSplitter(int nCount) (b&Z\?"
{ W[]|Uu/%
nSplitter = nCount; ,HmGp
} ^^tTA^
} .pm%qEh
)hoVB
W_Y56@7e
/* $vYy19z
**Utility.java yfR0vp<&
*/ KM"?l<x0Y
package NetFox; 7!m<d,]N
'"rm66
5nceOG8
public class Utility { Nlwt}7
Z("N *`VP;
CWYOzqf
public Utility() qt"6~r!
{ vk(I7
7M5HvG#w%
v4uQ0~k~X
} ?:l:fS0:{
5INw#1~
//线程睡眠 2bw.mp&v1
public static void sleep(int nSecond) ;'Z"CbS+
{ -4F}I3I
try{ xcQ^y}JN
Thread.sleep(nSecond); D(dV{^} 9
} oY,{9H37b
catch(Exception e) :J2^Y4l2
{ f><V;D#
e.printStackTrace (); v@s"*E/PF7
} ;4/ n~
} k+je-%hPj
.Zs.O/
//日志 erTly2-SJ
public static void log(String sMsg) 5xNOIOpDB
{ a[sdYZ
System.err.println(sMsg); Xa$%`
} aM,g@'.=
2~r2ErtS
v~._]f$:
public static void log(int sMsg) s=E6HP@q
{ xt`a":lru
System.err.println(sMsg); HL>l.IG?
} EUH9R8)
} _z.CV<
s*i,Ph
Lk^bzW>f
/* c*"P+
**TestMethod.java IEJ)Q$GI#
*/ Txpj#JD
package NetFox; wGIRRM !b
(R RRG;*n#
6!*zgA5M'
public class TestMethod { j/E(*Hv
J\'f5)k
bS55/M w
public TestMethod() cP@H8|c=
{ ///xx/weblogic60b2_win.exe fmUrwI1 %
try{ ^r7KEeVD
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .i` -t"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %P#| }
SiteFileFetch fileFetch = new SiteFileFetch(bean); a8k`Wog
fileFetch.start(); GU Mf}y
} 9]tW;?
catch(Exception e){e.printStackTrace ();} M.)z;[3O
G2@'S&2@s
]<q!pE;t
} ["ocZ? x
`(O#$n
$,I@c"m{
public static void main(String[] args) JlEfUg#*
{ ;4v`FC>
new TestMethod(); ,,)'YhG(
} $!z.[GL
} P(C5@x(Z
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