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)); k/%#>
} 59V#FWe-
for(int i=0;i<nEndPos.length-1;i++) BbFa=H.
{ Hal7 MP
nEndPos = nStartPos[i+1]; Z;#%t.
} "[k1D_PZ
nEndPos[nEndPos.length-1] = nFileLength; ful#Px6m
} FC6xFg^
} d:A}CBTSY
WrNLGkt
J0=7'@(p
//启动子线程 UcgG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Odm#wL~E
for(int i=0;i<nStartPos.length;i++) IE2CRBfs
{ YQ; cJ$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N1%p"(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bG"HD?A_
nStartPos,nEndPos,i); "jT#bIm
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1@xP(XS
fileSplitterFetch.start(); S@x}QQ|.
} UEzsDJu
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K4C^m|e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |pJC:woq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g+/0DO_F3
nEndPos = " + nFileLength); j.DHqHx
// fileSplitterFetch[nPos.length-1].start(); $*k)|4
^oYPyk`9
%;7.9%
//等待子线程结束 z5'ZN+
//int count = 0; k}GjD2m
//是否结束while循环 Y,C=@t@_
boolean breakWhile = false; ]fZ<`w8u}
/#f^n]v
v,{h:
while(!bStop) KF_?'X0=
{ f-4.WW2FN
write_nPos(); 'TL2%T/)t
Utility.sleep(500); 9e!vA6Fx
breakWhile = true; 9RH"d[%yc}
BWh}^3?l
v9=}S\=Cd
for(int i=0;i<nStartPos.length;i++) s.VA!@F5
{ $/+so;KD
if(!fileSplitterFetch.bDownOver) } ~| k
{ l;OYUq~F
breakWhile = false; [>f]@>
break; /prYSRn8
} Z0$] tS
} %]!adro~
if(breakWhile) obO}NF*g^
break; u^=`%)
T?n-x?e
%t*[T
//count++; ~h! 13!
//if(count>4) Hy]
// siteStop(); zzJja/mp
} xST4}Mb^f
>^=gDJ\a
zPR8f-Uvw
System.err.println("文件下载结束！"); %m eLW&
} ,X68xk.'
catch(Exception e){e.printStackTrace ();} eCWPhB6l
} e`iEy=W
:lgi>^
IxOc':/jY
//获得文件长度 z}+i=cAN
public long getFileSize() )u*^@Wo
{ GKZN}bOm\
int nFileLength = -1; *)'Vvu<
try{ @E%DP9.I
URL url = new URL(siteInfoBean.getSSiteURL()); L[y Pjw:0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )#C mQXgG
httpConnection.setRequestProperty("User-Agent","NetFox"); zT[6eZ8m
w^HjZV
(u&`Ij9
int responseCode=httpConnection.getResponseCode(); e4\dpvL
if(responseCode>=400) W\8Ln>
{ Z(e^iH
processErrorCode(responseCode); $'{=R 45Z
return -2; //-2 represent access is error jnJZ#=)
} ]a?bzOr,
$shp(T,q
t>xd]ti
String sHeader; (RE2I
U%>'"
_Zc4=c,K
for(int i=1;;i++) bMm3F%FFq&
{ d(;4`kd*N
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gmP9j)V6
//Utility.log(in.readLine()); 19t{|w<
sHeader=httpConnection.getHeaderFieldKey(i); |quij0_'e
if(sHeader!=null) F}Srn;V
{ X(Qu{HhI
if(sHeader.equals("Content-Length")) $4m*kQ
{ $SY]fNJQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uwmQ?LS]V
break; TTZe$>f
} B{MaMf)
} V'pqxjfd
else jVWK0Zba
break; qf#)lyr<D6
} poT&-Ic[
} tg\|?
catch(IOException e){e.printStackTrace ();} 2eb1lJdS
catch(Exception e){e.printStackTrace ();} lG:kAtx4
!L$x:/R9M
)OP){/
Utility.log(nFileLength); Q.Aa{d9e
Kz?#C
8)j@aiF`
return nFileLength; [XR$F@o
} nP3 E
MYdO jcN
56}X/u
//保存下载信息（文件指针位置） h8{(KRa6
private void write_nPos() 33Az$GXFsq
{ 2C=Q8ayvX
try{ 7DD&~ZcD
output = new DataOutputStream(new FileOutputStream(tmpFile)); #7G*GbKY
output.writeInt(nStartPos.length); J G$Z.s
for(int i=0;i<nStartPos.length;i++) G~,:2 o3
{ WsGths+[
// output.writeLong(nPos); lioc`C:
output.writeLong(fileSplitterFetch.nStartPos); Dw6fmyJ:
output.writeLong(fileSplitterFetch.nEndPos); b:W-l?
} E4z)Mr#
output.close(); (?0`d
} bHE2,;o
catch(IOException e){e.printStackTrace ();} r! %;R?c
catch(Exception e){e.printStackTrace ();} |nUl\WRd\
} 78 f$6J q
ac{?+]8}
?)D^~/ A
//读取保存的下载信息（文件指针位置） C[sh,
private void read_nPos() 6gL-OJNo
{ iUi>y.}"P
try{ |{>ER,<-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &@FhR#pUQ
int nCount = input.readInt(); }<a^</s
nStartPos = new long[nCount]; SmwQET<H
nEndPos = new long[nCount]; !69&Ld
for(int i=0;i<nStartPos.length;i++) zi@]83SS#
{ &7e)O=
nStartPos = input.readLong(); qet>1<
nEndPos = input.readLong(); 8^/I>0EZ
} X}ma]
input.close(); WJH\~<{mP
} )!:sFa 1
catch(IOException e){e.printStackTrace ();} c2nKPEX&5
catch(Exception e){e.printStackTrace ();} zAzP,1$?
} &ANP`=
n2B){~vE
')Y'c
private void processErrorCode(int nErrorCode) MGS-4>Q#
{ yw-8#y
System.err.println("Error Code : " + nErrorCode); r!1D*v5&:
} %EbPI)yY3
Zdc63fllM
Mj#-j/{x{5
//停止文件下载 W !w,f;
public void siteStop() XRx+Dddt;
{ EOj"V'!
bStop = true; b?X.U}62_
for(int i=0;i<nStartPos.length;i++) /P|fB]p
fileSplitterFetch.splitterStop(); Fb`a~c~s
'7^M{y/dU
RD7^&
} CAq/K?:8
} `.jzuX
//负责部分文件的抓取 f5AjJYq1
**FileSplitterFetch.java \wcam`f
*/ {%lXYMyu
package NetFox; 'rp }G&m
bV+(b9
>@xrs
import java.io.*; &Mq~T_S
import java.net.*; \>LnLH(
Q/uwQo/
Z;Ez"t&U
public class FileSplitterFetch extends Thread { [qUN4x5b
MTg:dR_
a7zcIwk '{
String sURL; //File URL M>9-=$7
long nStartPos; //File Snippet Start Position fZ04!R
long nEndPos; //File Snippet End Position ^z1&8k"[^
int nThreadID; //Thread's ID kft#R#m
boolean bDownOver = false; //Downing is over %,Sf1fUJ
boolean bStop = false; //Stop identical 3s\.cG?`r
FileAccessI fileAccessI = null; //File Access interface [FA{x?vkf
c\B|KhDk
Vtc36-\1*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *_a@z1
{ x-OA([;/
this.sURL = sURL; poGc a1
this.nStartPos = nStart; !tfb*@{;'
this.nEndPos = nEnd; ;c~cet4
nThreadID = id; S#)Eom?V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @k[R/,#'[t
} F<>!kK/c
S5~VD?O,
,@1p$n
public void run() A+6 n#
{ eSWLrryY
while(nStartPos < nEndPos && !bStop) 7+X:LA~U
{ 4wC+S9I#E^
l^ZI* z7N
O+g3X5f+
try{ * #jsgj[
URL url = new URL(sURL); | N0Z-|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q0f3="
httpConnection.setRequestProperty("User-Agent","NetFox"); L}@c6fHG
String sProperty = "bytes="+nStartPos+"-"; :RoBl3X=
httpConnection.setRequestProperty("RANGE",sProperty); y_\p=0t8
Utility.log(sProperty); (WJ${OW
?A(QyaKz
nKW*Y}VO
InputStream input = httpConnection.getInputStream(); x77l~=P+!
//logResponseHead(httpConnection); fP.F`V_Y
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^Ge+~o?x
byte[] b = new byte[1024]; T]2q?;N
int nRead; :'#TCDlOb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]-ZEWt6lsc
{ me[DmiM,
nStartPos += fileAccessI.write(b,0,nRead); ylt`*|$
//if(nThreadID == 1) 0-~\ W(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X]\ \,
} 9U$EJN_G
^G6RjJxqp8
vAyFmdJ^
Utility.log("Thread " + nThreadID + " is over!"); (aD_zG=k5
bDownOver = true; 5:'hj$~|\1
//nPos = fileAccessI.write (b,0,nRead); z9aY]lHY
} K~@Mg1R
catch(Exception e){e.printStackTrace ();} '1M7M(va
} gy&[?m6M=
} W5SJ^,d)J
|V<h=D5W
035rPT7-2-
//打印回应的头信息 v|U(+O
public void logResponseHead(HttpURLConnection con) ^f# FI&
{ os/vtyP:a
for(int i=1;;i++) [IK )
{ R: l&2k@
String header=con.getHeaderFieldKey(i); V}\~ugN)y
if(header!=null) @}u9Rn*d;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ],P;WPU
Utility.log(header+" : "+con.getHeaderField(header)); v{}#?=I5
else ,"B+r6}EF
break; Iu$K i
} =i~}84>
} -jMJAYjV
G "73=8d
lo[.&GD
public void splitterStop() foQ#a
{ 6`f2-f9%iq
bStop = true; ">#wOm+ +
} cReB~wk
Mbb x`
33!oS&L
} o7|eMe?<t
]xuG&O"SBV
0qX3v<+[6
/* Th=eNL]
**FileAccess.java lV%N
*//文件访问(定位，写) hiQha5
package NetFox; V7/I>^X
import java.io.*; Q[nEsYP
mauI42
Q=]w !I\
public class FileAccessI implements Serializable{ !Y-98<|b M
|+T1XYG5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ztw@Y|<2
RandomAccessFile oSavedFile; V O3x~E
long nPos; z<yU-m2h
q5?# 3T=
JU4qzi
public FileAccessI() throws IOException ^k]XEW{PG
{ *hw\35%P`?
this("",0); b[`Yi1^]%g
} B>2tZZko
at)~]dG
f"<O0Qw
public FileAccessI(String sName,long nPos) throws IOException xP[n
{ /n>qCuw
oSavedFile = new RandomAccessFile(sName,"rw"); M%@!cW
this.nPos = nPos; lyGhdgWc
oSavedFile.seek(nPos); h=:Q-?n-
} JfR%L q~
m}X`> aD/
1;{Rhu7* k
public synchronized int write(byte[] b,int nStart,int nLen) vvm0t"|\
{ sQ fFu
int n = -1; L31HGH2l
try{ 8?%-'z.
oSavedFile.write(b,nStart,nLen); 7x@A%2J
n = nLen; YxP&7oq
} 7(5 4/
catch(IOException e) >"C,@cN}B
{ 62Z#YQ}x
e.printStackTrace (); [Nk3|u`h
} )Q.>rX,F
5=Di<!a;
ndkti5L,
return n; ( vca&wI!
} 9T1ZL5
u,UmrR
|]c8jG\h
} 49vcoHlf
Qc pm!
R;j!}D!4
/* e:5bzk!~
**SiteInfoBean.java <>8WQn,K
*/ c`o7d)_Ke
package NetFox; }b-g*dn]5
~x|F)~:0=
uH(f$A
public class SiteInfoBean { s{$(*_
D ^x-^6^
8@tPm$
private String sSiteURL; //Site's URL ](s'L8(x
private String sFilePath; //Saved File's Path 6*3.SGUY
private String sFileName; //Saved File's Name RS^lKJ1 U
private int nSplitter; //Count of Splited Downloading File q,+yqrt
eN^qG 42
43@{JK9G
public SiteInfoBean() /\hzb/
{//nSplitter的缺省值为5 HbxL:~:}J
//default value of nSplitter is 5 |g//g\dd
this("","","",5); ]]*7\ :cb
} D/Mi^5H)
sPR1?:0:
MP>dW nl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v~^{{O
{ $GTU$4u
sSiteURL= sURL; fe9LEM8j
sFilePath = sPath; ;t|Ii8Ne
sFileName = sName; ^G.B+dG@`x
this.nSplitter = nSpiltter; Y$?9Zkp>
Ym =FgM\
3yB!M
} J%,*isEL
|563D#?cR
[@5Ytv H
public String getSSiteURL() 5.MGaU^Z$
{ ;ShJi
return sSiteURL; 28UU60
} H kQ)n3
/so8WRu.
iLkZ"X.'|1
public void setSSiteURL(String value) TZY3tUx0|G
{ <OIIoB?t
sSiteURL = value; dF2nEaN0%
} 4x 8)gE
|v({-*7
/!3@]xz*
public String getSFilePath() PEW=@xj2y
{ %@6}GmK^
return sFilePath; jW 3c"
} LILQ\I<<'
3GUZ;jdn
3U7*>H
public void setSFilePath(String value) T>NDSami
{ vy\RcP
sFilePath = value; .8by"?**
} *tK\R&4,4s
5) pj]S!]-
Z)SY.iK.
public String getSFileName() s]f6/x/~
{ &2{tF
return sFileName; !Rhlf.x
} !Ikt '5/
hMykf4
v#U"pn|M
public void setSFileName(String value) W7 #9jo
{ p_${Nj
sFileName = value; =g|IG [V
} n}!PO[m~
!& z(:d
.MP !`
public int getNSplitter() .P7"e5ge
{ (A~/'0/
return nSplitter; Z2'Bk2 L
} 4*Hgv:0?kI
0 g?z&?
'|Kmq5)
public void setNSplitter(int nCount) F*3j.lI
{ p(/dBt[3k
nSplitter = nCount; 'a\%L:`
} .K p
} >8qQK r\"
@CZT
7r~~Y%=C|
/* Lcg)UcB-#
**Utility.java -T[lx\}
*/ yL2o}ZbS
package NetFox; F)'.g d
0a-0Y&lQm
Stu4t==U
public class Utility { \uza=e
t3&LO~Ye
$**r(HV
public Utility() Ljx(\Cm
{ d ysC4DS
&3TEfvz
X ><?F|#7T
} HLV2~5Txc
!3*(N8_|#
//线程睡眠 [&#/]Ul'
public static void sleep(int nSecond) `CgaS#
{ P dhEQ}H
try{ n8".XS
Thread.sleep(nSecond); <7j87
} BA%pY|"Q
catch(Exception e) '<ZlGFt'n
{ 'gPzm|f|t@
e.printStackTrace (); k6sI L3QJ0
} }Du}c3
} 'i4_`^:+
,Qe?8En[
//日志 tm#nUw
public static void log(String sMsg) ZI3Nq
{ #nK>Z[
System.err.println(sMsg); X0haj~o[
} + EGD.S{
w(/aiV
#w\~&0
public static void log(int sMsg) YQ6f}O
{ @!yMIM%P
System.err.println(sMsg); 7:)n$,31FW
} s3R(vd
} %sX$nmi3
=p=rg$?
r0,:J
/* Fpa_qjL;
**TestMethod.java :F{:Z*Fi0
*/ .7.b:Dn0
package NetFox; |!"`MIw,
r?Wk<>%>
.xH5fMj,"
public class TestMethod { 83Q4On
(+FfB"3]
%|oJ>+
public TestMethod() k|lcc^[0
{ ///xx/weblogic60b2_win.exe }DK7'K
try{ znaUBv_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8\5 T3AF
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yl1gx
SiteFileFetch fileFetch = new SiteFileFetch(bean); C86J IC"
fileFetch.start(); a+!tT!g&I
} 7lBAxqr2
catch(Exception e){e.printStackTrace ();} .QN>z-YA6:
pnbIiyV
wT:b\km:!
} t-0a7 1#e
-< &D
L&%s[
public static void main(String[] args) !VI]oRgP
{ DIzH`|Y
new TestMethod(); b+&%1C
} tjluk
} A#95&kJpy
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