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)); `ux U H#
} D:U:( pg
for(int i=0;i<nEndPos.length-1;i++) n@mWBUM
{ }>=k!l{
nEndPos = nStartPos[i+1]; 3205gI,
} K~5QL/=1
nEndPos[nEndPos.length-1] = nFileLength; p}hOkx4R\
} 3aQWzEnh
} :t8(w>oW
=M>1;Qr<Z/
D%N^iJC,9
//启动子线程 =2BGS\$#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j#"?Oe{_1
for(int i=0;i<nStartPos.length;i++) t(-noy)
{ GN /]^{D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YBN@{P$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _p\
nStartPos,nEndPos,i); qgvg MWj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L@2T
fileSplitterFetch.start(); }a,j1r_Hl&
} 5*xk8*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r ioNP(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mEmznA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fmXA;^%
nEndPos = " + nFileLength); &/d;4Eu
// fileSplitterFetch[nPos.length-1].start(); 1D&Q{?RM
'^'vafs-/@
".O+";wk
//等待子线程结束 x1W<r)A )r
//int count = 0; y5 $h
//是否结束while循环 ZMy0iQ@
boolean breakWhile = false; d_BECx<\
YgNt>4K
^]3Y11sI
while(!bStop) sWP5=t(i+9
{ 5m!FtHvm1
write_nPos(); Cb7f-Eag
Utility.sleep(500); tI|?k(D
breakWhile = true; K4YpE}]u
'due'|#^
$J>GCY
for(int i=0;i<nStartPos.length;i++) dkt'~
{ ;t{Ew+s
if(!fileSplitterFetch.bDownOver) dFFJw[$8w
{ Q<3=s6@T
breakWhile = false; XZLo*C!MG
break; @tWyc%t
} ME7jF9d
} bYGK}:T8U
if(breakWhile) 1T a48
break; `9n%Dy<
9}Ud'#E
oA%8k51>~K
//count++; m!3b.2/h
//if(count>4) BoE;,s>]NW
// siteStop(); "rOe J~4 X
} $@"o BCc
,4zwd@&O
3`S|I_$(T"
System.err.println("文件下载结束！"); 9"Oz-!Y4
} >j5) MF{"
catch(Exception e){e.printStackTrace ();} G.OAzA13!t
} eVyXh>b*
1{i)7:Y
9>\P]:
//获得文件长度 CpNnywDRwU
public long getFileSize() o?$kcI4
{ ]ppi962Z
int nFileLength = -1; y.AVH`_u
try{ \Z-T)7S
URL url = new URL(siteInfoBean.getSSiteURL()); r63_|~JVB<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 55MrsiW
httpConnection.setRequestProperty("User-Agent","NetFox"); _\hZX|:]
")'o5V
YhYcqE8
int responseCode=httpConnection.getResponseCode(); 17AJT
if(responseCode>=400) Dj}n!M`2I
{ .[%em9u
processErrorCode(responseCode); +b"RZ:tKp
return -2; //-2 represent access is error bwR_ uF
} Q?-HU,RBO
+ntrp='7O7
aG.j0`)%
String sHeader; 7p%W)=v
qq"&Bc>
6FNs4|(d
for(int i=1;;i++) 9?a-1
{ dznHR6x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,#3u.=IR[
//Utility.log(in.readLine()); {WQH
sHeader=httpConnection.getHeaderFieldKey(i); 20750G
if(sHeader!=null) Oa~|a7`o
{ MG)wVS<d_
if(sHeader.equals("Content-Length")) M>W-lp^3
{ ,3l=44*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J0CEZ
break; fmyyQ|]O"
} ~WXT0-,
} FjF:Eh
else }_93}e
break; B?`n@/
} dR~4*59Bg
} qplz !=
catch(IOException e){e.printStackTrace ();} N=FU>qbz
catch(Exception e){e.printStackTrace ();} qu- !XC0p
l*_%K}%?V
2g5Ft
Utility.log(nFileLength); ^HYmi\`
Seh[".l
tZ,vt7
return nFileLength; [~03Z[_"/
} KdY3
4+%;eY.A
8}9|hT;
//保存下载信息（文件指针位置） RzCC>-
private void write_nPos() S-V)!6\cK
{ I{Hl2?CnI,
try{ y3l3XLI*b
output = new DataOutputStream(new FileOutputStream(tmpFile)); eFDhJ
output.writeInt(nStartPos.length); ?O(KmDH
for(int i=0;i<nStartPos.length;i++) 4|*b{Ni
{ #RAez:BI
// output.writeLong(nPos); ?w6zq|
output.writeLong(fileSplitterFetch.nStartPos); 7KIOI,qb6
output.writeLong(fileSplitterFetch.nEndPos); L".Qf|b*
} -;pZC}Nd3
output.close(); ,,1H#;j
} #v!(uuq,
catch(IOException e){e.printStackTrace ();} EOJk7
catch(Exception e){e.printStackTrace ();} "{>I5<:t
} %"tLs%"7=P
?w'a^+H
E*VUP5E
//读取保存的下载信息（文件指针位置） qjcy{@ j
private void read_nPos() 2,,zN-9mt
{ 9Fb|B
try{ YI05?J}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T \%{zz_(
int nCount = input.readInt(); s`"o-w\$>
nStartPos = new long[nCount]; [P,YW|:n
nEndPos = new long[nCount]; C@+"d3
for(int i=0;i<nStartPos.length;i++) 3GVE/GtU
{ @y:mj \J9
nStartPos = input.readLong(); %-ih$ZY
nEndPos = input.readLong(); l%"[857
} k^3 ?Z2a
input.close(); |O0=Q,<m
} *?jU$&Qpj*
catch(IOException e){e.printStackTrace ();} 46(Vq|
catch(Exception e){e.printStackTrace ();} 0tbximmDb
} i*34/
#hL<9j
{Ic~}>w
private void processErrorCode(int nErrorCode) $nN`K*%
{ )o!y7MTl
System.err.println("Error Code : " + nErrorCode); 0{M=^96
} }#~@HM>6Z
U-.?+`
`L<f15][
//停止文件下载 7oY}=281
public void siteStop() @k+Z?Hp
{ 4T#B7wVoM
bStop = true; P(?i>F7s
for(int i=0;i<nStartPos.length;i++) g7*cwu
fileSplitterFetch.splitterStop(); q~*3Bk~
Mf0!-bu
e='bc7$
} XVXiiQ^
} BLxtS
//负责部分文件的抓取 !(\OT
**FileSplitterFetch.java 'VA\dpa{J
*/ "=)i'x"0"
package NetFox; W[S4s/)mg
_r!''@B
o6f^DG3*
import java.io.*; ]{0R0Gr94
import java.net.*; 0Yz &aH
{l&6=z
,EPs>#d
public class FileSplitterFetch extends Thread { sO7$b@"u.
ca>6r`
c +Pg[1-
String sURL; //File URL l!Q |]-.@
long nStartPos; //File Snippet Start Position [s?H3yQ.
long nEndPos; //File Snippet End Position $ijWwrh
int nThreadID; //Thread's ID C6Qnn@waYb
boolean bDownOver = false; //Downing is over I"awvUP]a[
boolean bStop = false; //Stop identical TTjj.fq6
FileAccessI fileAccessI = null; //File Access interface Y9F78=Q
SI_{%~k*B
a<+Qw'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $<^4G
{ C~o6]'+F_
this.sURL = sURL; y- S]\tu
this.nStartPos = nStart; vn;_|NeSf
this.nEndPos = nEnd; F 7+Gt Ed
nThreadID = id; |a@$KF$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p"^^9'`=
} "B`yk/GM]
e6s-;
>o{(f
public void run() F5Ce:+h
{ YpQ/ )fSEV
while(nStartPos < nEndPos && !bStop) zjd]65P
{ =IBdnEz:M
dP0!?J Y
0Eq.l<
try{ r1:S8RT;H5
URL url = new URL(sURL); Ko%&~C_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T xRa&1
httpConnection.setRequestProperty("User-Agent","NetFox"); ]X4 A)4y
String sProperty = "bytes="+nStartPos+"-"; b6=.6?H@4f
httpConnection.setRequestProperty("RANGE",sProperty); k#k!AcC
Utility.log(sProperty); IQ$l!)
Nx4_Oc^hY
PN0l#[{EN
InputStream input = httpConnection.getInputStream(); }vBk,ED
//logResponseHead(httpConnection); .Ajs0 T2
eK\ O>
\ ?['pB
byte[] b = new byte[1024]; (mXV5IM
int nRead; kQlXcR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~ar8e
{ DmAMr=p
nStartPos += fileAccessI.write(b,0,nRead); *,1^{mb
//if(nThreadID == 1) #p~tkQ:'1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k!E`Xeob
} SPA_a\6_
A S;ra,x
?}^e,.M0?s
Utility.log("Thread " + nThreadID + " is over!"); mJb>)bOl
bDownOver = true; pLMki=.Ld
//nPos = fileAccessI.write (b,0,nRead); '3=[xVnv
} Uxx=$&#
catch(Exception e){e.printStackTrace ();} ]t_AXKd
} (_-<3)q4
} 'LIJpk3J
oPRvd_~
reLYtv
//打印回应的头信息 m<005_Z0Q
public void logResponseHead(HttpURLConnection con) [>#?C*s
{ 04NI.Jv
for(int i=1;;i++) &s_O6cqgh
{ `9b/Q
String header=con.getHeaderFieldKey(i); k{Yj!C> #
if(header!=null) 4VLrl8$K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cF_`m
Utility.log(header+" : "+con.getHeaderField(header)); 5{qFKo"g@,
else w'ZL'/d
break; m *8[I
} O?NAbxkp
} lwPK^)|}
I"*g-ji0
/HH5Mn*
public void splitterStop() (qHI>3tpY
{ n5"rSgUtE
bStop = true; 2-nL2f!a{p
} cX"[#Em#
(i>VJr
_m0HgLS~
} rFZB6A<(]
5~4I.+~8
dsqqq,>Q
/* jy{T=Nb
**FileAccess.java x, a[ p\1
*//文件访问(定位，写) 95^w" [}4Q
package NetFox; h";G vjy
import java.io.*; ("o<D{A
Y>Q9?>}Q
laqKP+G
public class FileAccessI implements Serializable{ {'G@-+K
h;f5@#F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 iyrUY
RandomAccessFile oSavedFile; orf21N+[
long nPos; RvV4SlZz
9a2Ga
N8}R<3/
public FileAccessI() throws IOException fHYEK~!C04
{ K,%H*1YKK
this("",0); IJO`"da
} "QACQ-
Fgxh?Wd9
hJ#U;GL
public FileAccessI(String sName,long nPos) throws IOException ~\DC )
{ Sj(uc#
oSavedFile = new RandomAccessFile(sName,"rw"); sIdo(`8$
this.nPos = nPos; l*("[?>I
oSavedFile.seek(nPos); N:[m,U9a
} 3Gf^IV-
A_T-]YQ
qdm5dQ (c
public synchronized int write(byte[] b,int nStart,int nLen) U*,8,C
{ J]nb;4w
int n = -1; EnA) Rz
try{ O[y.3>l[s
oSavedFile.write(b,nStart,nLen); IPa08/
n = nLen; LslQZ]3MY
} `R0>;TdT
catch(IOException e) L7_Mg{
{ U2/H,D
e.printStackTrace (); 5.F.mUO
} @no]*?Gpa
%m!o#y(hD`
hE-`N,i}
return n; $&nF1HBI4
} =#n05*^
e"hm|'
Yi&;4vC
} V\%;S
IV;juFw}G
:ZL;wtT
/* \`jFy[(Pa'
**SiteInfoBean.java #nX0xV5=
*/ _)p@;vGV
package NetFox; n99:2r_
yEtI5Qk
ygS*))7 r
public class SiteInfoBean { $$<9tqA
SG |!wH^
t*zve,?}
private String sSiteURL; //Site's URL _s (0P*
private String sFilePath; //Saved File's Path 9c9-1iS
private String sFileName; //Saved File's Name vLDMa>
private int nSplitter; //Count of Splited Downloading File 2V/A%
;gy_Qf2U
.}kUD]pW
public SiteInfoBean() kOETx
{//nSplitter的缺省值为5 a+)Yk8%KY
//default value of nSplitter is 5 f'TjR#w
this("","","",5); sn2SDHY
} ?`AzgM[I
?*K;+@EH
f'\I52;FB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {}N*e"<O
{ wJ1qJ!s@
sSiteURL= sURL; lg&"=VXx51
sFilePath = sPath; %;^[WT`,
sFileName = sName; g$ZgR)q
this.nSplitter = nSpiltter; b:\I*WJ
LpaY Md;
a36n}R4Q
} k^z)Vu|f.
d"Y9go"Z
!sEI|47{
public String getSSiteURL() fW!~*Q
{ . Uv7{(
return sSiteURL; ss T o?WL|
} /],:sS7
P9:7_Vc
!w]!\H
public void setSSiteURL(String value) y1cAw
{ 6=Kl[U0Y
sSiteURL = value; RZjTUMAz4
} [WXtR
_D1bR7
,[,+ _A
public String getSFilePath() yx3M0Qo
{ g~h`wv'
return sFilePath; '`T.K<
} v+znKpE
YNn,{Xi
ymY,*Rb
public void setSFilePath(String value) hZY+dHa]
{ kWjCSC>jA
sFilePath = value; Au#(guvm
} 0?BT*
Ooc,R(
Zla5$GM
public String getSFileName() Ag }hyIl
{ ?qAX *j
return sFileName; zu(/c
} Ec8Y}C,{7<
cInzwdh7
BqvOi~l
public void setSFileName(String value) gmLGK1
{ FgE6j;
sFileName = value; D*Siy;
} \! Os!s
=y,_FFoS
7`6n]4e
public int getNSplitter() D2E~c? V
{ D`3}j
return nSplitter; vpvPRwJ
} aN).G1
L;Nz\sJ
#?}k0Y
public void setNSplitter(int nCount) +I/7eIG?|
{ ~d/Doi
nSplitter = nCount; v#IW;Rj8
} %g5weiFM
} E+dr\Xhv
@,CCwiF'q
QJTGeJ Y
/* }=^YLu=
**Utility.java $ENA$
*/ F&lWO!4
package NetFox; ORs<<H.d
LV0g *ng
ZWG$MFEjl
public class Utility { ]d9;YVAU
r|fJ~0z
&w*.S@ ;
public Utility() 6f?5/hq
{ !a[ voUS
'dQ2"x?4
:o*{.
} Fb*^GH)J
UB|Nx(V s
//线程睡眠 y,DK@X
public static void sleep(int nSecond) 4sSQ nK
{ !Lb9KDk
try{ Kk!D|NKLC
Thread.sleep(nSecond); r444s8Y
} J*.Nf)i
catch(Exception e) tU!"CX
{ Dgc[WsCEW
e.printStackTrace (); ``1#^ `
} P{)&#HXUVb
} 5f=e JDo=x
FxKH?Rl
//日志 7xVI,\qV
public static void log(String sMsg) bo$xonV@y
{ b}9K"GT
System.err.println(sMsg); Xleoh2&M
} :)q/8 0@
r*>XkM& M
4^w>An6
public static void log(int sMsg) RB\>$D
{ bG^E]a/D
System.err.println(sMsg); CmJI"
} G-Sw`HHo
} e3F)FTG&
#fG!dD42
H[*.Jd
/* .m7iXd{
**TestMethod.java *Y9"-C+
*/ <gZC78}E
package NetFox; AQbbIngo
c<A@Op"A
"h_n/}r=
public class TestMethod { s+yBxgQ/
A0oC*/
6}L[7~1
public TestMethod() W7l/{a @
{ ///xx/weblogic60b2_win.exe *VIM!/YW
try{ e l'^9K
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6y%BJU.I
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); s)375jCga
SiteFileFetch fileFetch = new SiteFileFetch(bean); hs2f3;)
fileFetch.start(); (vz)GrH>
} d7It}7@9
catch(Exception e){e.printStackTrace ();} W2%(a0p
5;>M&qmN
Z&s+*&TM
} ;T"}dJel#
_"%d9B
^KF
public static void main(String[] args) $*xnq%A
{ Z#w1,n88
new TestMethod(); I =qd\
} W5 fO1F
} R|$=Pfg~4
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