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)); s@K)RhTY
} C3Q[L}X\
for(int i=0;i<nEndPos.length-1;i++) *z;4. OX
{ W}bed],l
nEndPos = nStartPos[i+1]; Vo<V!G{
} tvynl;Y/
nEndPos[nEndPos.length-1] = nFileLength; b[Sd$ACd
} j2SJ4tB /
} * F%Wf
oCdWf63D
b;#3X)
//启动子线程 wl #Bv,xf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5G cdz
for(int i=0;i<nStartPos.length;i++) e5_a.c
{ wq!Gj]B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?9nuL}m!a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $5ZBNGr
nStartPos,nEndPos,i); XRCiv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "l vPge
fileSplitterFetch.start(); jIwz G+)$P
} ^{nf0)56c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]#;;)K}>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JsI`#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yKF"\^`@
nEndPos = " + nFileLength); .'JO7of
// fileSplitterFetch[nPos.length-1].start(); {/G~HoY1i
;75K:_
1=gE,k5H
//等待子线程结束 A ><
//int count = 0; YKKZRlQo
//是否结束while循环 e/JbRbZX
boolean breakWhile = false; &?flH;
kx0(v1y3gT
42E]&=Cet
while(!bStop) Bee`Pp2
{ /MYl:>e>
write_nPos(); (CFm6p'RZ
Utility.sleep(500); 6U5L>sQ
breakWhile = true; {Qbg'|HO=l
F \6-s`(
|N, KA|Gdq
for(int i=0;i<nStartPos.length;i++) H<41H;m
{ (~ro_WC/I
if(!fileSplitterFetch.bDownOver) Hy=';Ccn}
{ TLbnG$VQS
breakWhile = false; k?]`PUrV
break; 3NU{7,F
} & -L$B
} R5OP=Q8
if(breakWhile) Aiyx!Q6vT
break; QS(aA*D
MiHa'90{K
mY6d+
//count++; cW%QKdTQY0
//if(count>4) *} @Y"y
// siteStop(); w]<V~X
} wJc~AP)I%z
LFvO[&
; '6`hZ
System.err.println("文件下载结束！"); 9O(vh(C
} y,&'nk}
catch(Exception e){e.printStackTrace ();} u NmbR8Mx
} s'$5]9$S
GZ=7)eJ~<
_A]8l52pt
//获得文件长度 1,Ams
public long getFileSize() s"OP[YEke/
{ jGm`Qg{<
int nFileLength = -1; >qE f991SZ
try{ hSAdD!
URL url = new URL(siteInfoBean.getSSiteURL()); <O<Kf:i&c1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GgT 5'e;N
httpConnection.setRequestProperty("User-Agent","NetFox"); B'NtG84
_\"2Mdk`]
+"mS<
int responseCode=httpConnection.getResponseCode(); y~ 2C2'7
if(responseCode>=400) UTWchh
{ g2RrBK,
processErrorCode(responseCode); 1s-dqHz"s
return -2; //-2 represent access is error 8NF93tqD6
} `GDWy^-Q+!
4*0C_F@RX
,r5'nDV=d
String sHeader; QT8GP?F
W(4Mvd
%3%bRP
for(int i=1;;i++) [,bra8f[C
{ @GVONluyU`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); C(%b!Q,2
//Utility.log(in.readLine()); T0;8koj^_
sHeader=httpConnection.getHeaderFieldKey(i); nmo<t]
if(sHeader!=null) aRV.;S
{ zi^?9n),
if(sHeader.equals("Content-Length")) Y+d+
{ ;7>k[?'e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rD;R9b"J
break; v]GQb
} EJW}&e/
} >Jk]=_%
else 6}cN7wnm j
break; GU|(m~,`
} ~H c5M5m
} *!.anbo@?z
catch(IOException e){e.printStackTrace ();} r3NdE~OAi
catch(Exception e){e.printStackTrace ();} hLr\;Swyp
5c\dm
ES\=MO5a7
Utility.log(nFileLength); }60/5HNr
g/4ipcG;N
x }@P
return nFileLength; LP'wL6#
} n%6ba77
^kK% 8 u
%i.Prckrb
//保存下载信息（文件指针位置） |s,y/svp
private void write_nPos() f~R+Q/Gtz`
{ >QdT7gB
try{ ]*hH.ZBY"^
output = new DataOutputStream(new FileOutputStream(tmpFile)); UyAy?i8K
output.writeInt(nStartPos.length); :O7n*lwx
for(int i=0;i<nStartPos.length;i++) h=4 GSU
{ &3OV|ly]
// output.writeLong(nPos); )O2IEwPd.
output.writeLong(fileSplitterFetch.nStartPos); /E!N:g<
output.writeLong(fileSplitterFetch.nEndPos); {DapXx
} hEFOT]P4
output.close(); ]v]tBVO$
} Q ZC\%X8j
catch(IOException e){e.printStackTrace ();} of {K{(M7@
catch(Exception e){e.printStackTrace ();} M.HMnN#
} ~e&O?X
/Pxny3
yJ="dEn>i"
//读取保存的下载信息（文件指针位置） (*_lLM@Cd
private void read_nPos() {.?pl]Zl6
{ 9o4h~Imu
try{ G^';9 UK
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ' &3,qT
int nCount = input.readInt(); hV+=hX<h
nStartPos = new long[nCount]; kS?CKd9by
nEndPos = new long[nCount]; E3] 8(P%D-
for(int i=0;i<nStartPos.length;i++) p:)=i"uL
{ dai+"
nStartPos = input.readLong(); {9@u:(<X9
nEndPos = input.readLong(); &KY!a0s
} ;!C_}P
input.close(); _u'y7-
} pSI8"GwQ
catch(IOException e){e.printStackTrace ();} ?bpVdm!
catch(Exception e){e.printStackTrace ();} VkO*+"cGv
} 4U16'd
"LSzF_mK
eco&!R[G
private void processErrorCode(int nErrorCode) IA{W-RRb
{ |fIyq}{7
System.err.println("Error Code : " + nErrorCode); m@u%3*:
} tj*/%G{Y
hu1ZckIw?
1/~=61msc
//停止文件下载 z{FFTb^B
public void siteStop() Vh>cV
{ 4 R(m$!E!
bStop = true; h5pfmN\-5
for(int i=0;i<nStartPos.length;i++) dGi HO
fileSplitterFetch.splitterStop(); N>,`TsUwW
t=xEUOQAn
n>R(e>
} =<#G~8WYz
} ."=%]l0
//负责部分文件的抓取 aidQ,(PDj
**FileSplitterFetch.java AFm9"mQrw
*/ >Q!}tbg~9
package NetFox; Je6wio-4
5 7t.Ud
g2m*Q%
import java.io.*; fK+ 5
import java.net.*; xOAq!,|V
G_J}^B*?%v
R y#C#0
public class FileSplitterFetch extends Thread { ZQ+DAX*MS
83SK<V6
}8#Ed;%K
String sURL; //File URL u~j H
long nStartPos; //File Snippet Start Position d+,!p8Q
long nEndPos; //File Snippet End Position m7g*zu2#
int nThreadID; //Thread's ID 2dkWzx
boolean bDownOver = false; //Downing is over )LIn1o_,
boolean bStop = false; //Stop identical WV.hQX9P
FileAccessI fileAccessI = null; //File Access interface .ex;4( -!
!?0C(VL(:
=>`zk^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException NRJp8G Z%U
{ l^nvwm`f#:
this.sURL = sURL; (C#0 ML
this.nStartPos = nStart; cI@qt>&
this.nEndPos = nEnd; &C+2p
nThreadID = id; T+@i;M
fileAccessI = new FileAccessI(sName,nStartPos);//定位 n}IGxum8`
} 8|=C/k
1:](=%oM&k
gmbRH5k
public void run() Wn+s:ov
{ n19A>,m
while(nStartPos < nEndPos && !bStop) GZu12\0nZ
{ 'QG`^@Z
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UIyLtoxu
try{ x4c|/}\)*
URL url = new URL(sURL); j67ppt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'Xj^cX
httpConnection.setRequestProperty("User-Agent","NetFox"); V<S6a
String sProperty = "bytes="+nStartPos+"-"; ^C~Ryw7
httpConnection.setRequestProperty("RANGE",sProperty); sIf]e'@AC
Utility.log(sProperty); F&R*njJcc
zgEN2d
2I_ yUt-
InputStream input = httpConnection.getInputStream(); EA>.SSs!
//logResponseHead(httpConnection); F<g&t|@
?[zw5fUDS
?# FYF\P
byte[] b = new byte[1024]; 5aW#zgxXg
int nRead; cWx`y><
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yjL+1_"B
{ A)"L+Yu5
nStartPos += fileAccessI.write(b,0,nRead); s=(q#Z
//if(nThreadID == 1) PB$beQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jOzXyDq
} 8bdO-LJ9
02t({>`
iKrk?B<
Utility.log("Thread " + nThreadID + " is over!"); SXqB<j$.;
bDownOver = true; )m;*d7l~p
//nPos = fileAccessI.write (b,0,nRead); u*2?Gky
} S:j{R^$k
catch(Exception e){e.printStackTrace ();} 4Z%1eOR9V
} . KLEx]f.
} #)~u YQ
bKsjbYuo
@z ",1^I
//打印回应的头信息 d~~, 5E
public void logResponseHead(HttpURLConnection con) W/BPf{U
{ /.7RWy`
for(int i=1;;i++) =9ff983
{ e7"T37
String header=con.getHeaderFieldKey(i); xAd@.^
if(header!=null) Wx]Xa]-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [yN+(^i
Utility.log(header+" : "+con.getHeaderField(header)); _?O'A"
else 7d%x7!E
break; ``jNj1t{}
} %f&Y=
} qA)YYg/G
s$pXn&:
B@M9oNWHu
public void splitterStop() g=nb-A{#
{ _:Xmq&<W
bStop = true; Nf!N;Cy?
} iS+"Jsz
.kFO@:
}ZVond$y4
} b)'CP Cu*
GgY8\>u
v}u]tl$,
/* .+(V</
**FileAccess.java 50Gr\
*//文件访问(定位，写) ~wuCa!!A
package NetFox; td7(444]
import java.io.*; -(?/95 Y
@-[}pZ/
FCNYfjB%
public class FileAccessI implements Serializable{ 5n2!Y\
C lf;+G0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {H[N|\
RandomAccessFile oSavedFile; 7d>w]R,Z
long nPos; Q/?`);
&v .S_Ym
@Nsn0-B?ne
public FileAccessI() throws IOException ^ 34Ng
{ `ZEFH7P
this("",0); c6vJ;iz
} ,e'm@d$Q*
id9QfJ9t
3?V'O6
public FileAccessI(String sName,long nPos) throws IOException trrNu
{ -y!Dg6A
oSavedFile = new RandomAccessFile(sName,"rw"); THQ #zQ-
this.nPos = nPos; u~uz=Yse
oSavedFile.seek(nPos); |MGT8C&^!
} 7I w^
c\o_U9=n
3G4WKg.^
public synchronized int write(byte[] b,int nStart,int nLen) LAk .f
{ ]'xci"qV`
int n = -1; GEy7Vb)
try{ BN]o!Y
oSavedFile.write(b,nStart,nLen); M**Sus87Q
n = nLen; N~/X.D4e#
} ]_B<K5
catch(IOException e) }Y!V3s1bm
{ 2H$](k?
e.printStackTrace (); DDmC3
} JzN "o'
yWZ_
gnN>Rl 5_
return n; NqF*hat
} .CEC g*f
E!}'cxb^
o0No"8DnjH
} YvG$2F|_)
Cw:|(`9
Hz,Gn9:p
/* ?84f\<"
**SiteInfoBean.java hb8oq3*x
*/ HkRvcX 5
package NetFox; Vr1r2G2
l5^Q
+/$&P3
public class SiteInfoBean { (BH<\&yHE
%6fnL~A
n,2p)#?
private String sSiteURL; //Site's URL nl2Lqu1
private String sFilePath; //Saved File's Path @+~URIG)
private String sFileName; //Saved File's Name H{E(=S
private int nSplitter; //Count of Splited Downloading File tAjT-CXg
![{/V,V]~
\l0!si
public SiteInfoBean() vbd ;Je"
{//nSplitter的缺省值为5 O '#FVZ.g
//default value of nSplitter is 5 gYho$E
this("","","",5); L1lDDS#
} ;gHcDnH)
Qj [p/H$
v^/<2/E"?4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b't6ekkN
{ \A!Iln
sSiteURL= sURL; ,lCFe0>k!=
sFilePath = sPath; V=1yg24B<
sFileName = sName; KvPLA{
this.nSplitter = nSpiltter; U\{I09@E 0
B2BG*xa
F-~Xbz%
} WzdlrkD
CucW84H`J
FbdC3G|oA
public String getSSiteURL() # NK{]H$fd
{ fe6Op
return sSiteURL; d`?EEO
} H-WNu+
w3>G3=b
|~Awm"
public void setSSiteURL(String value) Xn!=/<TIVz
{ u0uz~ s
sSiteURL = value; Y8mv[+Z
} 2<2a3'pG
eEmLl(Lb
1mEW]z
public String getSFilePath() O1]XoUH<
{ 9 771D
return sFilePath; !C.{nOfyv
} G<*h,'B
,=%c e
[h\_yU[P
public void setSFilePath(String value) 7vH4}S\ q
{ d?CU+=A&|
sFilePath = value; }u5J<*:bZ
} .= 8Es#
5kv]k?
6~k qU4lL
public String getSFileName() M?$tHA~OX
{ O#U_mgfzJ
return sFileName; P6tJo{l8w
} Z\$!:
4T<dI6I0
j!"NEh78H
public void setSFileName(String value) 5_L43-
{ o{| |Ig
sFileName = value; %cMayCaI!@
} J=DD/Gp
^A;ec h7I
1Imb"E
public int getNSplitter() JDMsco+j5
{ klj.\wg/p{
return nSplitter; Yr:$)ap
} _lk5\bu
Qc:Sf46O
RKz _GEH)
public void setNSplitter(int nCount) ZW8;?#_
{ xWty2/!h
nSplitter = nCount; -(.\> F
} y\[GS2nTX
} a% 82I::t
&sPu3.p
Hkj| e6
/* O`(it%Ho!
**Utility.java f]^ @z<FC
*/ {S5D~A*a+
package NetFox; n%P,"V
Rv+p4RgA
?x =Sm|Ej
public class Utility { Fd0\T#k
^TY8,qDA
51M'x_8
public Utility() rxIYgh
{ v]KI=!Gs
y/A<eHLy
X<$8'/p r
} : ]JsUb{YK
\"@`Rf
//线程睡眠 >za=v
public static void sleep(int nSecond) L`Q9-#Y
{ `r8bBzr@%
try{ 8 K>Ejr
Thread.sleep(nSecond); ,}42]%$G
} 9]/ju
catch(Exception e) W.U|mNJ$
{ \~q cYp
e.printStackTrace (); o!t1EPJE*
} -wV0Nv(V8
} 38q0iAH
Y~bGgd]T
//日志 ma4r/8Q
public static void log(String sMsg) z'}?mE3i
{ Aonq;} V e
System.err.println(sMsg); ud.Bzg:/
} mJ5LRpXN
u~d&<_Z
/waZ9
public static void log(int sMsg) :`P;(h
{ }tT*Ch?u
System.err.println(sMsg); pBu~($%d
} 4==LtEp
} Swz1RT
KGX?\#-
#8d$%F))
/* wbId}!
**TestMethod.java ^5~[G%G4
*/ $T0|zPK5
package NetFox; Vkb&' rXw+
2={ g'k(
BPd]L=,/
public class TestMethod { 8)k.lPoo.
T't^pO-`
~dwl7Qc
public TestMethod() XfT6,h7vFL
{ ///xx/weblogic60b2_win.exe _n{6/
try{ U-s6h;^O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); OkO"t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \rf1#Em
SiteFileFetch fileFetch = new SiteFileFetch(bean); {w^flizY
fileFetch.start(); Yazpfw 7'd
} ;@d<*
catch(Exception e){e.printStackTrace ();} 5y"yd6O]O5
aV(*BE/@F
1|cmmUM-'v
} ]yVB66l
m x,X!}
9AL\6@<a*
public static void main(String[] args) Krq^|DY
{ nw5#/5xw
new TestMethod(); J= |[G'
} m9xu$z|e
} y9)l,@D
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