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)); R 5-q{
} <k<K"{
for(int i=0;i<nEndPos.length-1;i++) KtchKpv
{ =dx!R ,Bw
nEndPos = nStartPos[i+1]; _Db=I3.HJ
} CL.JalR`b
nEndPos[nEndPos.length-1] = nFileLength; K#rfQ0QK/!
} OSQZ5:g|
} S<rdPS*P
au@ LQxKQ
,;)Y1q}Q
//启动子线程 }l~|c{WH`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L^i=RGx
for(int i=0;i<nStartPos.length;i++) Nz_c]3_j
{ 7cW9@xPe
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X,n4_=f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cjAKc|NJ
nStartPos,nEndPos,i); T6h-E^Z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ."&,_F
fileSplitterFetch.start(); id<i|
} SNV~;@(h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )Fx"S.Ok
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9]fhH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M(|Qvh{Q6
nEndPos = " + nFileLength); v".q578 0B
// fileSplitterFetch[nPos.length-1].start(); fftFNHP
JQ=i{9iJ
_x&;Fa%
//等待子线程结束 eQu%TZ(x-$
//int count = 0; <f.*=/]W2
//是否结束while循环 gF-<%<RV
boolean breakWhile = false; Zu`; S#Y
h6<abT@I
~T@t7Cg
while(!bStop) BZejqDr*
{ |z\5Ik!fF]
write_nPos(); |x@)%QeC
Utility.sleep(500); PtCO';9[
breakWhile = true; NAjY,)>'K
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for(int i=0;i<nStartPos.length;i++) Yv k Qh{
{ d~F`q7F'?]
if(!fileSplitterFetch.bDownOver) ^`~M f
{ 2_M+akqy^
breakWhile = false; rqW[B/a{
break; Ls{z5*<FM
} b&[9m\AX`
} aSdh5?
if(breakWhile) HeABU(o4
break; 7ksh%eV
IhnHNY]<g
LOQoi8j
//count++; c.-h'1
//if(count>4) A}WRpsA9
// siteStop(); _a1 =?
} WA}<Zme3[
_J(n~"eR
xxkUu6x#
System.err.println("文件下载结束！"); /WlK*8C
} nv&uhu/q
catch(Exception e){e.printStackTrace ();} 1{+x >Pv:
} g?N~mca$
gw~%jD-2
bHVAa#
//获得文件长度 (uW/t1
public long getFileSize() qcMVY\gi
{ i;Cs,Esnf
int nFileLength = -1; pm$2*!1F(
try{ K*iy^}
URL url = new URL(siteInfoBean.getSSiteURL()); ,<?iL~> %
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d\aKGq;8C
httpConnection.setRequestProperty("User-Agent","NetFox"); u>c\J|K_V
9rXbv4{
w}+#w8hu
int responseCode=httpConnection.getResponseCode(); 7jvy]5y8&~
if(responseCode>=400) 8 2qf7`
{ NbOeF7cq+
processErrorCode(responseCode); j1_ E^
return -2; //-2 represent access is error j,%@%upM
} xw_VK1
vzV,} S*c
n][/c_]q
String sHeader; 3ThBy'
06DT2
} 8ZCWmd
for(int i=1;;i++) 5v"r>q[ X
{ Gr9/@U+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vSty.:bY\p
//Utility.log(in.readLine()); X"WKgC g$
sHeader=httpConnection.getHeaderFieldKey(i); T=r-6eN
if(sHeader!=null) r=GF*i[3
{ q/y4HT,x
if(sHeader.equals("Content-Length")) MuNM)pyxp
{ 5`qt82Qm
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,XT#V\qne
break; ,M2u (9
} A4LGF
} Z$qFjWp
else 3t<XbHF9
break; U'^AJ2L8
} +5J"G/f
} 'J^ M`/
catch(IOException e){e.printStackTrace ();} bwh7.lDAl
catch(Exception e){e.printStackTrace ();} s ^NO(
mF!/8qk
[ZwZGAP
Utility.log(nFileLength); yMdEH-?/
`$og]Dn;
zNSix!F
return nFileLength; iVq4&X_x
} @L^Fz$Sx
.d< +-w2Mu
<viIpz2jh%
//保存下载信息（文件指针位置） u@|izRk
private void write_nPos() aE}1~`
{ R=M"g|U6
try{ 0kN;SSX!
output = new DataOutputStream(new FileOutputStream(tmpFile)); JA W}]:jC
output.writeInt(nStartPos.length); blxAy
for(int i=0;i<nStartPos.length;i++) .G[y^w)w}
{ ,#3}TDC
// output.writeLong(nPos); kp3(/`xP
output.writeLong(fileSplitterFetch.nStartPos); y*2R#jTA
output.writeLong(fileSplitterFetch.nEndPos); /dTy%hZC}
} #PnuR2s7.
output.close(); 5 e:Urv77
} )6|7L)Dk
catch(IOException e){e.printStackTrace ();} `(A6uakd
catch(Exception e){e.printStackTrace ();} =PHl|^
} 3/IQ]8g"
$ tf;\R
W-wy<<~f
//读取保存的下载信息（文件指针位置） g*b 4N_
private void read_nPos() [vki^M5i|Z
{ ?]%JQ]Gf*
try{ xsK{nM6g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :LRR\v0HM
int nCount = input.readInt(); TJ(PTB;
nStartPos = new long[nCount]; _'&N01
nEndPos = new long[nCount]; A^7!:^%K
for(int i=0;i<nStartPos.length;i++) VlKy6PSIg
{ w+VeT@
nStartPos = input.readLong(); 8+vZ9!7
nEndPos = input.readLong(); L'{;V\d
} A.7:.5Cx'
input.close(); lhg3 }dW
} T!$7:% D
catch(IOException e){e.printStackTrace ();} E_&Hje|J_[
catch(Exception e){e.printStackTrace ();} ".L+gn}u-
} 9fD4xkRS
OJE<2:K
k5G(7Ug=g~
private void processErrorCode(int nErrorCode) >yvP[$]!6
{ T=cSTS!P;q
System.err.println("Error Code : " + nErrorCode); Rf@D]+v
} ;SQ<^"eK
\V@SCA'
*Yv"lB8
//停止文件下载 2&91C[da0
public void siteStop() R_h(Z{d
{ E [JXQ76
bStop = true; 1A^iUC5)
for(int i=0;i<nStartPos.length;i++) i} 96,{
fileSplitterFetch.splitterStop(); PJj{5,#@3
|| ?B1
5A1oZ+C#
} RsBo\#`
} EQPZV K/
//负责部分文件的抓取 o;Ijv\Em
**FileSplitterFetch.java 4W8rb'B!Ay
*/ w?ssV
package NetFox; IV^LYu
dsDoPo0!
5_Yv>tx
import java.io.*; BOJh-(>I
import java.net.*; ~WuElns
vl$! To9R"
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public class FileSplitterFetch extends Thread { Pb?H cg
_5a]pc$\Y]
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String sURL; //File URL 7ka^y k@Q
long nStartPos; //File Snippet Start Position i]GBu
long nEndPos; //File Snippet End Position !s,<hU#
int nThreadID; //Thread's ID c5P52_@
boolean bDownOver = false; //Downing is over R7*Jb-;$!
boolean bStop = false; //Stop identical Wq)'0U;{$
FileAccessI fileAccessI = null; //File Access interface A{h hnrr8
, >Y.!
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $m/-E#I#Z
{ <mHptgd,
this.sURL = sURL; L1BpkB
this.nStartPos = nStart; ]6OrL TmP
this.nEndPos = nEnd; uuj"Er31
nThreadID = id; N&NOh|YS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 HY#7Ctn3
} zcJ]US
;]fpdu{
hgj#VY$B
public void run() j>&n5?
{ [2w3c4K
while(nStartPos < nEndPos && !bStop) y- k?_$M
{ 4 E3@O
,- ]2s_
cYx=8~-
try{ ZJ"*A+IJx[
URL url = new URL(sURL); ==x3|^0y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qU8UKIP
httpConnection.setRequestProperty("User-Agent","NetFox"); VR?7{3
String sProperty = "bytes="+nStartPos+"-"; <6<uO\B\
httpConnection.setRequestProperty("RANGE",sProperty); w:FH2*
Utility.log(sProperty); &_4A6
UTA0B&aB
+lJuF/sS8m
InputStream input = httpConnection.getInputStream(); 37p0*%a":
//logResponseHead(httpConnection); #BS]wj2#
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SUD]Wl7G`r
byte[] b = new byte[1024]; =)M8>>l
int nRead; -Kg@Sj/U}R
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'lC"wP&$
{ '5ky<
nStartPos += fileAccessI.write(b,0,nRead); XyS#6D
//if(nThreadID == 1) u4VQx,,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]&/jvA=\l,
} R'dF<&Kj|
3JW9G04.
fH`1dU
Utility.log("Thread " + nThreadID + " is over!"); C*Ws6s>+z
bDownOver = true; BT>*xZLpS
//nPos = fileAccessI.write (b,0,nRead); Aog3d\1$
} 0nx <f>n
catch(Exception e){e.printStackTrace ();} 344,mnAd
} j,/o0k,
} W\.f:"2qr
/<:9NP'^
;x^&@G8W`
//打印回应的头信息 H'gPGOd
public void logResponseHead(HttpURLConnection con) lG#&Pv>-
{ K'?ab 0
for(int i=1;;i++) bG^eP:r
{ Jr17pu(t
String header=con.getHeaderFieldKey(i); 4n3QW%#
if(header!=null) 2IjqTL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hN\E8"To
Utility.log(header+" : "+con.getHeaderField(header)); ^Jnp\o>
else R2]?9\II
break; :NbD^h)R
} O.rk!&N
} v@>hjie
h(/|`
](MXP,R
public void splitterStop() 7h&xfrSrD
{ t ?bq~!X
bStop = true; /SMp`Q88
} S\0"G*
:\80*[=;Z
*otJtEI>6
} Yf{s0Z
W@wT,yJ8@
Gw+z8^|C&}
/* EVq<gGy
**FileAccess.java S}Mxm2
*//文件访问(定位，写) !@VmaAT
package NetFox; Kjz,p^Y\
import java.io.*; $ya#-pi`;
{g/\5Z\b
Z?nMt
public class FileAccessI implements Serializable{ Tr@`ozp8
?5B}ZMW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 AO']Kmm
RandomAccessFile oSavedFile; 5yA^n6
long nPos; uaU!V4-
7ZZSAI
2A`EFk7_X
public FileAccessI() throws IOException P45q}v
{ ke3=s
this("",0); *EV]8
} _^a.kF
/_}v|E0
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public FileAccessI(String sName,long nPos) throws IOException (^Nf;E
{ &q":o 'q
oSavedFile = new RandomAccessFile(sName,"rw"); hJd#Gc~*M
this.nPos = nPos; 2o\\qEYg
oSavedFile.seek(nPos); up:e0di{
} o.Cj+`0}5
i(c2NPbX
Q;aZpi-E"
public synchronized int write(byte[] b,int nStart,int nLen) E#HO0]S
{ &)bar.vw/
int n = -1; %{HqF>=~
try{ /@wm?ft6Gk
oSavedFile.write(b,nStart,nLen); wh*OD
n = nLen; l,v:[N
} Qy6Avw/$
catch(IOException e) ,%KB\;1mn'
{ (j-(fS
e.printStackTrace (); >Mvt;'c
} ^2mXXAQf7^
}>Os@]*'^(
w:umr#
return n; *:&fw'vd,
} @#T?SNIL5
p O: EJ
x&9I2"
} <c\aZ9+V
B]Zsn`n
LG,RF:
/* e,4!/|H:
**SiteInfoBean.java =r_ SMTu
*/ x65e,'
package NetFox; N`zHe*=[~
g:2/!tujL
mB1)!
public class SiteInfoBean { rBny*!n
BR0bf5T/
9s7B1Pf
private String sSiteURL; //Site's URL Pu9.Uwx
private String sFilePath; //Saved File's Path XkK16aLE
private String sFileName; //Saved File's Name &[Sw:{&*jv
private int nSplitter; //Count of Splited Downloading File KX9ZwsC0
/4T%&#6s
?v")Z0 ~
public SiteInfoBean() 94a_ W9
{//nSplitter的缺省值为5 3aDma/
//default value of nSplitter is 5 |2oB3 \)/
this("","","",5); +QHhAA$
} >K &b,o,[
S((8DSt*
gq0gr?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V!Joh5=a
{ ' l!QGKz
sSiteURL= sURL; lhjPS!A~
sFilePath = sPath; bX6*/N
sFileName = sName; D^TKv;%d
this.nSplitter = nSpiltter; _n_i*p '2
F_21`Hj
o3W5FHFAv
} u#P7~9ZG-
'PO1{&M
4o=G) KO{
public String getSSiteURL() X'u`\<&W
{ |j!D _j#U
return sSiteURL; 4B> l|%
} /z'j:~`E
R1wdQ8q
4({=(O
public void setSSiteURL(String value) ,>g 6OU2~6
{ .6'T;SoK>
sSiteURL = value; J`V6zGgW
} 3{c&%F~!
*FAg^G&1
N&ddO-r[s
public String getSFilePath() WI6er;D
{ K{iayg!k
return sFilePath; *1%g=vb
} {Ise (>V
\agC Q&
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public void setSFilePath(String value) eU12*(
{ )l"0:1Ig
sFilePath = value; S4(IYnwN
} S_QDYnF)`
t^[{8,N
I&vB\A
public String getSFileName() ~kHir]jc
{ ;zOZu~Q|'
return sFileName; Qz<-xe`o8]
} Hc+<(g
S2NsqHJr
bHMlh^{`%
public void setSFileName(String value) _9-Ajv
{ ]I]dwi_g)
sFileName = value; _<~05Eh
} '0=U+Egp
4 '+)9&g
~W#f,mf
public int getNSplitter() $K iMu
{ kQb0pfYs
return nSplitter; QxkfP%_g
} :C&?(HJ&r
af_zZf!0
4R0_%x6vG
public void setNSplitter(int nCount) t"L:3<U7
{ \Dc\H)
nSplitter = nCount; eJwr
} L"Gi~:z
} *[U:'o`67
q+DH2&E'
fg9sZ%67]\
/* _I!Xr!!)a0
**Utility.java &p%,+|
*/ z=xHk|+'
package NetFox; h}oQr0"c
'L m `L<`
G'epsD,.bX
public class Utility { b'&pJ1]]}
j NY8)w_
[X I5Bu ~
public Utility() Cse0!7_T
{ _E%[D(
mSzwx/3"
w iq{Jo#
} EW!$D
AVJk
//线程睡眠 tL5Xfd?u
public static void sleep(int nSecond) }/LYI
{ I*ej_cFQ^
try{ _c&*'IY[V
Thread.sleep(nSecond); 4EpzCaEZ
} Za} |Ee
catch(Exception e) m^=, RfUUd
{ V":BAn
e.printStackTrace (); S ~_%
} I45A$nV#Q
} {)[i\=,`{
ceOjuzY
//日志 ^AM_A>HnG
public static void log(String sMsg) :b>|U"ux
{ q5A+%#
System.err.println(sMsg); ELPJ}moWZ
} RgO 7> T\
~L1O\V i
lVFX@I=pI
public static void log(int sMsg) ^"Y'zIL
{ {$t*Mb0
System.err.println(sMsg); BuYDw*.
} W(8g3
} {aL$vgYT1
:}-u`K*
NWg\{a
/* cjR.9bgn
**TestMethod.java W wE)XE
*/ WU4i-@Bm8
package NetFox; sHuz10
V588Leb?
qh'BrYu*
public class TestMethod { JA}'d7yEa
^ZlV1G;/W@
g#:XN
public TestMethod() F:g{rm[
{ ///xx/weblogic60b2_win.exe 3azc`[hl
try{ )eEvyU
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :6/OU9f/R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); VqrMi *W6
SiteFileFetch fileFetch = new SiteFileFetch(bean); P~<93
fileFetch.start(); d{hYT\7~1(
} G"[pr%?
catch(Exception e){e.printStackTrace ();} l!y _P
D5>~'N3b
(0Qq rNs
} J9FNjM[qe
5jQP"^g
Fdw[CYHz
public static void main(String[] args) ."X~?Nk
{ de6dLT>m
new TestMethod(); nnNg^<[k3
} t4*A+"~j
} %MJ7u}
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