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)); Iu <?&9t
} F F|FU<
for(int i=0;i<nEndPos.length-1;i++) Pqn@ST
{ }nL7T'$>
nEndPos = nStartPos[i+1]; &sU?Ok6
} w'UVKpG+
nEndPos[nEndPos.length-1] = nFileLength; {QwHc5Bf
} ](s'L8(x
} +1D+]*t_?[
iB498t
43@{JK9G
//启动子线程 ?W)A
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h]TQn)X]
for(int i=0;i<nStartPos.length;i++) [DF,^4g
{ 7D;cw\ |
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hUF5fZqii
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~FN9 [aJF+
nStartPos,nEndPos,i); xjVS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yI"6Da6|y
fileSplitterFetch.start(); 1#ft#-g}
} @9lUSk^9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P9vA7[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /%;mqrdk
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hX=A)73(
nEndPos = " + nFileLength); d&+h}O
// fileSplitterFetch[nPos.length-1].start(); cj1cZ-
ekWePL;rR2
LL3#5AA"k|
//等待子线程结束 "*Tb" 'O
//int count = 0; vuoQz\
//是否结束while循环 hBBUw0"
boolean breakWhile = false; 6,0_)O}\b
5Er2}KZJv,
*^:N.&]
while(!bStop) \Z+z?K O
{ #3+!ee27#
write_nPos(); TL}++e 7+
Utility.sleep(500); (G[ *|6m
breakWhile = true; )3>hhuaa
{qN 5MsY
%'X[^W
for(int i=0;i<nStartPos.length;i++) D"a~#^
{ |v({-*7
if(!fileSplitterFetch.bDownOver) /!3@]xz*
{ PEW=@xj2y
breakWhile = false; 'LE=6{#
break; }n4V|f-
} #~<0t(3Q
} #g]vc_V
if(breakWhile) `0Oh_8"
break; "$2y-|
n:{qC{D-qS
'coV^~qy
//count++; pLLGus+W
//if(count>4) Bi @2
// siteStop(); %>g3~yl
} `#;e)1
m>MB7,C;N
"-vW,7y
System.err.println("文件下载结束！"); f PM8f
} *U P@9D
catch(Exception e){e.printStackTrace ();} EV*IoE$W]=
} d%V*|0c)
tF{D= ;G
/assq+H
//获得文件长度 {/ BT9|LI
public long getFileSize() "gDb1h)8
{ =*r])Vg^
int nFileLength = -1; CnG+Mc^
try{ 3_MS.iM
URL url = new URL(siteInfoBean.getSSiteURL()); i? K|TC`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =5(>q5Z*
httpConnection.setRequestProperty("User-Agent","NetFox"); $w);5o
{M^3m5.^
RT.D"WvT
int responseCode=httpConnection.getResponseCode(); -UOj>{-
if(responseCode>=400) d~JKH&x<
{ i;_tI#:A
processErrorCode(responseCode); MMx9(`t*.
return -2; //-2 represent access is error PqiB\~o@Z
} T^Ze3L]
9Ru8~R/\
B4i!/@0s
String sHeader; g.zEn/SM
yL2o}ZbS
F)'.g d
for(int i=1;;i++) z$?~Y(EY
{ Vv.|br`;}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R'!
//Utility.log(in.readLine()); 5a hVeY
sHeader=httpConnection.getHeaderFieldKey(i); -6n K<e`
if(sHeader!=null) ,I%g|'2
{ +i@y@<l:+
if(sHeader.equals("Content-Length")) !3*(N8_|#
{ mg$]QnbAnH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `CgaS#
break; P dhEQ}H
} n8".XS
} >VN5`Zlw\C
else '>' wK.
break; 5sx1Zq7
} vM*($qpAy
} q@nP}Pv&5
catch(IOException e){e.printStackTrace ();} ~e+\k>^eN
catch(Exception e){e.printStackTrace ();} >U]C/P[+
(3{YM(
to=y#$_
Utility.log(nFileLength); a*ushB
{O7X`'[
%\H|B0
return nFileLength; o!{w"K
} C ihAU"
7]||UuF<
~1W x=
//保存下载信息（文件指针位置） }}>q2y
private void write_nPos() 32/MkuY^u
{ ,z-}t& _t
try{ K%F,='P}
output = new DataOutputStream(new FileOutputStream(tmpFile)); $0lD>yu
output.writeInt(nStartPos.length); MBhWMCN2
for(int i=0;i<nStartPos.length;i++) BE_ay-
{ .7.b:Dn0
// output.writeLong(nPos); |!"`MIw,
output.writeLong(fileSplitterFetch.nStartPos); 06N}k<10O
output.writeLong(fileSplitterFetch.nEndPos); !,Va(E|=
} X@LRsg
output.close(); -/g B|J
} CJJzCVj
catch(IOException e){e.printStackTrace ();} :QB<?HaS'
catch(Exception e){e.printStackTrace ();} 9&` 2V
} b/{t|io{
.tzG_
:]^P1sH[
//读取保存的下载信息（文件指针位置） NT+?#0I
private void read_nPos() H=Y{rq@
{ Ux}(?Z
try{ Bhp-jq'!B
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _PlKhv}
int nCount = input.readInt(); )Ccq4i
nStartPos = new long[nCount]; pXtXjb
nEndPos = new long[nCount]; j{9D{
for(int i=0;i<nStartPos.length;i++) nAjO6g6E
{ [`rba'
nStartPos = input.readLong(); glF; eT
nEndPos = input.readLong(); 8F&=a,ps[
} qIIv6''5@
input.close(); {yB&xj[z
} aM:nOt" S1
catch(IOException e){e.printStackTrace ();} $l|qk z
catch(Exception e){e.printStackTrace ();} HLZ;8/|48m
} U~j ^I^
0QOBL'{7)
W^]3XJP
private void processErrorCode(int nErrorCode) 'zGo?a
{ s#tZg
System.err.println("Error Code : " + nErrorCode); p~,]*y:XT
} ^k#P5oV
_J? Dq
T3pmVl
//停止文件下载 Ou1JIxZ)|
public void siteStop() }0X:F`Y-
{ "0cID3A$
bStop = true; ek}a}.3 {
for(int i=0;i<nStartPos.length;i++) zOa_X~!@
fileSplitterFetch.splitterStop(); V*iH}Y?^p
nY`RRC
2VJR$Pao
} %^>ju;i^O
} !Y\D?rKZ
//负责部分文件的抓取 <RG|Dx[:=
**FileSplitterFetch.java DFd%9*N
*/ NF0%}II&xK
package NetFox; o)2W`i&
)8UWhl=
AbYqf%~7`l
import java.io.*; .On|uC)!
import java.net.*; /gu%:vq
LM-J !44
hijgF@
public class FileSplitterFetch extends Thread { GrAujc5|
pn.T~"%
'_/Bp4i
String sURL; //File URL fmiz,$O4?
long nStartPos; //File Snippet Start Position x>*Drm 7
long nEndPos; //File Snippet End Position v!ujj5-$I
int nThreadID; //Thread's ID yzLpK;
boolean bDownOver = false; //Downing is over JMz;BAHT
boolean bStop = false; //Stop identical 7e#?e+5+A
FileAccessI fileAccessI = null; //File Access interface yA.4G_|I
T|dY 2
]5$eAYq
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H+ 0$tHi
{ 6^"=dn6K
this.sURL = sURL; 'toa@5
this.nStartPos = nStart; nx^]>w
this.nEndPos = nEnd; F>-B3x
nThreadID = id; )Ib<F7v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *i- _6s
} r;Gi+Ca5
7qg{v9|,
]jaQ[g$F
public void run() P3nb2.
{ N.]qU d
while(nStartPos < nEndPos && !bStop) 8qu2iPOcZ
{ V%YiAr>
IS#FiH
zOqn<Y@
try{ !>e5z|1
URL url = new URL(sURL); }c`fW&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jlBanGs?
httpConnection.setRequestProperty("User-Agent","NetFox"); i]|Yg$
String sProperty = "bytes="+nStartPos+"-"; F;l$.9?.s
httpConnection.setRequestProperty("RANGE",sProperty); ,XIz?R>;c
Utility.log(sProperty); xgNJeQ
K,boVFs
|&[L?
InputStream input = httpConnection.getInputStream(); 5c^Z/ Jl$c
//logResponseHead(httpConnection); u a~CEs
5KDGSo
""1^k2fj
byte[] b = new byte[1024]; CFqJ/''
int nRead; p Wt) A
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;+<&8.=,)
{ 1!1beR]
nStartPos += fileAccessI.write(b,0,nRead); &b?LP]
//if(nThreadID == 1) `(f!*Ru@/z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sM?MLB\Za
} %T)oCjM[\
kWe{r5C7
}2uI?i8
Utility.log("Thread " + nThreadID + " is over!"); hvuIxqv!y
bDownOver = true; %9M~f*
//nPos = fileAccessI.write (b,0,nRead); 0LfU=X0#7
} &znQ;NH#
catch(Exception e){e.printStackTrace ();} KA){''>8
} & M~`:R
} LF~*^n>
Ircp``g
9f',7i
//打印回应的头信息 ZP;j9T!
public void logResponseHead(HttpURLConnection con) P '>SmQ
{ $T`<Qq-r
for(int i=1;;i++) )Lwc
{ 4&_NJ\
String header=con.getHeaderFieldKey(i); {e[c
if(header!=null) :bWUuXVtJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); NLrPSqz
Utility.log(header+" : "+con.getHeaderField(header)); OnF3lCmu
else IZ=Mlu
break; HE'2"t[a
} {iv<w8CU)
} dd\n8f
EvWzq%z l
5o6>T!
public void splitterStop() cu%C"
{ H]$)Eg%6
bStop = true; lNL6M%e$Q
} 't_[dSO
0MkSf*
=Uj-^qcE
} "v`
Z7_ zMM
)E,\H@A
/* y-j\zK
**FileAccess.java 1xbK'i:-S
*//文件访问(定位，写) B7]C]=${m
package NetFox; }yJ$SR]t
import java.io.*; *_KFW@bC:
,Vh{gm1
Y;e,Gq`
public class FileAccessI implements Serializable{ "7v@Rye
2con[!U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m<w"T7
RandomAccessFile oSavedFile; Ojt`^r!V
long nPos; wAz&"rS
+q)5dYRzV
Uv?|G%cD-
public FileAccessI() throws IOException EloMe~a3
{ OzQ -7|m'J
this("",0); ]Lm9^q14m
} 7yx$Nn`(
>A<bBK#
vk?skN@
public FileAccessI(String sName,long nPos) throws IOException 5i-Rglo
{ OI?K/rn
oSavedFile = new RandomAccessFile(sName,"rw"); ph_4q@
this.nPos = nPos; 7yz4'L
oSavedFile.seek(nPos); Vm df8[5
} n':!,a[
.p=sBLp8
*0}3t<5
public synchronized int write(byte[] b,int nStart,int nLen) Qhw^S*
{ %<\6TZr
int n = -1; !Yw3 d
try{ TD9;kN1`
oSavedFile.write(b,nStart,nLen); 8-lOB
n = nLen; 5 gv/Pq&
} ! /NG.Wf
catch(IOException e) J%jB?2 1:o
{ c= x,ijY "
e.printStackTrace (); qt3PXqR7:
} cI=r+OGk*
mCWhUBghR
BA:yQ
return n; 2PeR
} W0C@9&pn6
<N`J`J-[
#_|sgS?1
} K3' niGT
p?2Y }9
d~?X/sJ t
/* (s1k$@d
**SiteInfoBean.java |8.(XsN
*/ t2V0lyeL
package NetFox; `$~RxzZ g
Fk6x<^Q<w
8UMFq
public class SiteInfoBean { $rhgzpZ!X_
e{A9r@p!
+MB!B9M@
private String sSiteURL; //Site's URL b-Z4 Jo G
private String sFilePath; //Saved File's Path wBInq~K_
private String sFileName; //Saved File's Name xxm%u9@s
private int nSplitter; //Count of Splited Downloading File /c$\X<b);
r&2~~_d3y
D!oc>K$B
public SiteInfoBean() %&Fk4Z}M
{//nSplitter的缺省值为5 +*n-<x5"
//default value of nSplitter is 5 e.*%K!(
this("","","",5); cDoo*
} $%%os6y2v
+e-,ST&w(
e|rg;`AW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) WH$e2[+Y
{ F*Z=<]<+
sSiteURL= sURL; x%<
sFilePath = sPath; =B];?%
sFileName = sName; 1Fe^Qb5G
this.nSplitter = nSpiltter; `?y<>m*
-3&G"hfK
M^7MU}5w
} rFZrYm
`$YP<CJeq
jr /lk
public String getSSiteURL() $v`afd y
{ O Lc}_
return sSiteURL; )g|xpb
} a6h>=uT [
e2+BWKaU
=X!IHd0
public void setSSiteURL(String value) <|*'O5B
{ #"ftI7=42
sSiteURL = value; MzYavg`
} Z/6qG0feJ
$fpq 3
]{ d[
public String getSFilePath() {u\%hpD_
{ ~RBrSu)
return sFilePath; IhiGP {
} BYM3jXWi0v
R|P_GN6>
4<X!<]3]
public void setSFilePath(String value) |3{&@7
{ npDIX
sFilePath = value; zD)pF1,7:8
} DOQc"+
!>(RK"KWq]
OI0B:()
public String getSFileName() @+Y8*Rj\3
{ `T2<<<
return sFileName; J RPSvP\
} +y#T?!jQYj
O%f8I'u$
;XC@=RpX
public void setSFileName(String value) U{ ;l0 2S
{ e.o;eD}"
sFileName = value; *RR[H6B^]X
} f&hwi:t
C*I(|.i@
#Y93y\
public int getNSplitter() dp5f7>]:(
{ sLcFt1
return nSplitter; R 4wr
} +jqj6O@Tjr
jAND7&W
t=R6mjb
public void setNSplitter(int nCount) 6S.~s6o,
{ Hwm?#6\5
nSplitter = nCount; jko"MfJ
} 2uk x (Z
} 7@PIM5h
[<wbbvXR
=/+#PVO
/* X['2b78k
**Utility.java nN3$\gHp8i
*/ [ut#:1h^
package NetFox; Ra3ukYG[
!7U\J]
JeY'8B
public class Utility { ^*^/]vM
uO >x:*^8
bO<0qM~
public Utility() S^cH}-+
{ }wSy
HhkN^S,
D6Y6^eS-
} {BO|u{C
137Xl>nO
//线程睡眠 (\dK4JJ
public static void sleep(int nSecond) 2D([Z-<i
{ BN@,/m9OQ%
try{ mEQ!-p
Thread.sleep(nSecond); {$^SP7qV#>
} !Zbesp KZ
catch(Exception e) _a+ICqR
{ ex?\c"
e.printStackTrace (); RP(/x+V
} ewB!IJxh
} 8,o17}NY,
3AlqBXE"Z<
//日志 L8V3BH7B
public static void log(String sMsg) ?Ay3u^X
{ (Q-I8Y8l8
System.err.println(sMsg); qi+&|80T.
} [.q(h/b
vZajT!h
'H FKBp
public static void log(int sMsg) j[P8
{ aQcN&UA@
System.err.println(sMsg); (3md:r<-
} P 4;{jG
} &.*uc|{
B50 [O!
(BERY
/* k_3j '
**TestMethod.java Qa$NBNxKl
*/ v_sm
package NetFox; 7aQcP
7nz!0I^
hXX1<~k
public class TestMethod { 8mgQu]>
n=`w9qajd
viuiqs5[Bi
public TestMethod() "E>t, D
{ ///xx/weblogic60b2_win.exe p,n\__
try{ |5xzl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =w<VT%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y3yvZD
SiteFileFetch fileFetch = new SiteFileFetch(bean); G[q9A$yw
fileFetch.start(); 0RyFv+
} yx0Q+Sm1:
catch(Exception e){e.printStackTrace ();} O3!d(dY=_
:pd&dg!5
Bp0bY9xLg_
} <lOaor c
F14(;'Az
)!C7bTv 4
public static void main(String[] args) <*YO~S(R
{ w4{y"A
new TestMethod(); 8U^D(jrz
} IT1PPm
} nC~fvyd<P
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