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)); KBoW(OP4'
} vjVa),2
for(int i=0;i<nEndPos.length-1;i++) 3!h3flE
{ %(S!/(LWW
nEndPos = nStartPos[i+1]; ]|N"jr?7H
} .E9$j<SP-
nEndPos[nEndPos.length-1] = nFileLength; 4av
} )8taMC:H^
} b\^1P;!'W
iL<FFN~{
uF ;8B]"
//启动子线程 _}j6Pw'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g*-}9~
for(int i=0;i<nStartPos.length;i++) RT2&^9-
{ - i{1h"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ac,<+y7A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), j*FpQiBoT
nStartPos,nEndPos,i); i!G<sfL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hXD`OlX
fileSplitterFetch.start(); xouBBb=
} b)>l7nOc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <O41M\,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); QO>)ug+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _7R6%^
nEndPos = " + nFileLength); S"fqE%
// fileSplitterFetch[nPos.length-1].start(); R2qz>kyyB
uF{l`|b'
Pz|}[Cx-
//等待子线程结束 wH\ K'/
//int count = 0; A9WOu*G1O
//是否结束while循环 &?I3xzvK
boolean breakWhile = false; BwYR"
-^*8D(j*
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while(!bStop) djn<Oc`
{ t Kjk<
write_nPos(); uG/bCb+V
Utility.sleep(500); KkJE-k*D+w
breakWhile = true; ug/P>0
Ko!a`I2M}
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for(int i=0;i<nStartPos.length;i++) 6J965eM'[
{ &m`@6\N(
if(!fileSplitterFetch.bDownOver) <899r \
{ X;{U?`b-
breakWhile = false; ;T<'GP'/r
break; mp0s>R
} =T$2Qo8
} BOl*. t
if(breakWhile) ()fYhk|W
break; ?QcS$i
IFXnGDG$
'h>l_A
//count++; i7?OZh*f
//if(count>4) 4)9Pgp:
// siteStop(); ?#:!!.I:
} L(/wsw~y*
[3]h(D
(#Xgfb"S3
System.err.println("文件下载结束！"); R?] S<Z
} ?'$}k
catch(Exception e){e.printStackTrace ();} 08$l=
} "-Uqv@
@ 3b-
hAB:;r XlI
//获得文件长度 3ZAzv en
public long getFileSize() `)H| &!wT
{ o6X<FE#8
int nFileLength = -1; .Pa6HA !
try{ ?osYs<k \
URL url = new URL(siteInfoBean.getSSiteURL()); QjsN7h&%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LfsOGC
httpConnection.setRequestProperty("User-Agent","NetFox"); fM<g++X
MENrP5AL
\qbEC.-K
int responseCode=httpConnection.getResponseCode(); "; ?^gA
if(responseCode>=400) XE|"n
{ tTe:Oq
processErrorCode(responseCode); k")3R}mX
return -2; //-2 represent access is error Csm23QLsg)
} FFc?Av?_
z\<gm$1CB
$t>ow~Xi
String sHeader; rzKn5Z
,oj)`?Vh
=1j`VJU9
for(int i=1;;i++) jE$]Z(Ab
{ =l$qwcfbo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (<yQA. M
//Utility.log(in.readLine()); &wB?ks
sHeader=httpConnection.getHeaderFieldKey(i); W0Q;1${
if(sHeader!=null) h='@Q_1Sb
{ <gSZ<T
if(sHeader.equals("Content-Length")) .Tc?9X~4
{ }}v28"\TA
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g@S?5S.Av
break; !7uFH PK-
} h{Y#. j~aS
} I\VC2U
else T(bFn?
break; I=V]_Ik4N
} RTYhgq
} x;/%`gKn8
catch(IOException e){e.printStackTrace ();} r)Iq47Uiw
catch(Exception e){e.printStackTrace ();} ?E7.x%n7X5
av!~B,
D^2yP~(
Utility.log(nFileLength); +|Qe/8Q
G6j9,#2@
$!"*h
return nFileLength; v:Z.8m8D
} ^ `Y1
9Dx9alJR
}!Xj{Eoc
//保存下载信息（文件指针位置） xW'(]Z7_
private void write_nPos() -cWxS{vO
{ n]%yf9,w
try{ E9S&UU,K
output = new DataOutputStream(new FileOutputStream(tmpFile)); [3hOc/]s
output.writeInt(nStartPos.length); 2d-C}&}L\
for(int i=0;i<nStartPos.length;i++) f<( ysl1[
{ 4+r26S,T
// output.writeLong(nPos); Psu*t%nQ?A
output.writeLong(fileSplitterFetch.nStartPos); 24/ ^_Td
output.writeLong(fileSplitterFetch.nEndPos); 5I@2UvV8
} }5Pzen
output.close(); o*|j}hnbv
} }Gm/9@oKc
catch(IOException e){e.printStackTrace ();} ,46k8%WW
catch(Exception e){e.printStackTrace ();} <o\I C?A
} =Qw`F0t
sMAu*
=ZN~*HLl}
//读取保存的下载信息（文件指针位置） L-(.v*
private void read_nPos() fmq9u(!R
{ ZfN%JJOz(
try{ SgPvQ'\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eI*o9k$Qs
int nCount = input.readInt(); ~@bh[o~rF
nStartPos = new long[nCount]; Zae$M0)
nEndPos = new long[nCount]; q/yL={H?
for(int i=0;i<nStartPos.length;i++) OO+QH 2j
{ E14Dq#L
nStartPos = input.readLong(); +eD+Z.{
nEndPos = input.readLong(); KZSvT{
} >~k"C,6
input.close(); '`Iuf\
} eo&nAr
catch(IOException e){e.printStackTrace ();} weky 5(:
catch(Exception e){e.printStackTrace ();} l>O~^41[
} r+%}XS%;h
*R6Ed
K0O&-v0"1
private void processErrorCode(int nErrorCode) lZ9rB^!
{ P>3 ;M'KsO
System.err.println("Error Code : " + nErrorCode); \4OX]{
} * "Z5bKL
Sq,x57-
Cl5l+I\1
//停止文件下载 ^p433
public void siteStop() Q4,!N(>D
{ 3ud_d>
bStop = true; Wc+)EX~KS
for(int i=0;i<nStartPos.length;i++) $kef_*BQg
fileSplitterFetch.splitterStop(); oMV<Yn_<
/&#Gh?z
/ `Glf|
} XNJPf) T
} 3B5GsI
//负责部分文件的抓取 OWRT6R4v
**FileSplitterFetch.java G&HCOR!h
*/ 8=U0\<wT
package NetFox; TZk.?@s5
6eh\-+=
2=PX1kI
import java.io.*; tmJ-2
import java.net.*; ^%?*u;uU%
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public class FileSplitterFetch extends Thread { Ej]:j8^W
"ebm3t@C
Z4 +6'
String sURL; //File URL sV))Z2sq
long nStartPos; //File Snippet Start Position U\ Et
long nEndPos; //File Snippet End Position xQ=sZv^M
int nThreadID; //Thread's ID |99/?T-QW
boolean bDownOver = false; //Downing is over B~RVFc +
boolean bStop = false; //Stop identical jLRh/pbz4
FileAccessI fileAccessI = null; //File Access interface [Grd?mc#
%|:Gn)8
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D 1Q@4 g
{ TUQ+?[
this.sURL = sURL; #Jo#[-r
this.nStartPos = nStart; uoM;p'
this.nEndPos = nEnd; 8i=c|k,GL.
nThreadID = id; 1webk;IM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <n)J~B^
} Az}.Z'LJ
5mxYzu;#]
u._B7R&>
public void run() `EUufTYi
{ &]'{N69@d?
while(nStartPos < nEndPos && !bStop) ,u1Yn}
{ W/3,vf1
7)`U%}R
ke sg]K
try{ 2+7rLf`l
URL url = new URL(sURL); em+dQ15
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N<|_tC+ct
httpConnection.setRequestProperty("User-Agent","NetFox"); G98P<cyD
String sProperty = "bytes="+nStartPos+"-"; wsnR$FhQ`
httpConnection.setRequestProperty("RANGE",sProperty); aeQvIob@
Utility.log(sProperty); h2SVDKj
9Q<8DMX^
WPmH4L>T
InputStream input = httpConnection.getInputStream(); `m.).Hda
//logResponseHead(httpConnection); xV_,R'l
L"|~,SVF
}Ss]/_t
byte[] b = new byte[1024]; gkJL=,
int nRead; sw={bUr6G`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [\ M$a|K
{ o"te7nBI
nStartPos += fileAccessI.write(b,0,nRead); @%7IZg;P6
//if(nThreadID == 1) &Hb;; Ic(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b?p<y`
} -K 7jigac
M7O5uW`
eF[CiO8F2
Utility.log("Thread " + nThreadID + " is over!"); yMU>vr
bDownOver = true; </UUvMf"
//nPos = fileAccessI.write (b,0,nRead); g>m)|o'
} pSjJ u D
catch(Exception e){e.printStackTrace ();} ^PnXnH?
} =6XJr7Ay8u
} n9 LTrhLqp
[1-1^JY
toq/G,N Q
//打印回应的头信息 81gcM?
public void logResponseHead(HttpURLConnection con) k`l={f8C
{ S>-x<'Os
for(int i=1;;i++) |[/<[@\''
{ \3M<_73
String header=con.getHeaderFieldKey(i); BB x359
if(header!=null) 3pxZk%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ae1?8man
Utility.log(header+" : "+con.getHeaderField(header)); p#5U[@TK
else lO (MF
break; BHVC&F*>
} !cLdoX
} OcA_m.
W'|NYw_B
scf.>K2
public void splitterStop() 6x'F0{U
{ #%4XZ3j#j;
bStop = true; Ic 5TtN~/>
} B]KR*
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-YDA,.Ic?
} fH-fEMyW
!"v[\||1
/|<Pn!}J
/* 4YuJ-
**FileAccess.java S!Alno
*//文件访问(定位，写) ?/M:
package NetFox; O$qxo &
import java.io.*; .wU0F
sf([8YUd
,4Q1[K35B
public class FileAccessI implements Serializable{ D*%?0
fH@P&SX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^n|yfvR
RandomAccessFile oSavedFile; Wc*jTip
long nPos; y*G3dWb
x%v[(*F#y
R@X65o
public FileAccessI() throws IOException 4.=jKj9j
{ :F |ll?
this("",0); `!udU,|N
} oe'f?IY
qa\e`LD%Y
HzMr
public FileAccessI(String sName,long nPos) throws IOException JdM0f!3
{ %(uYYr 6
oSavedFile = new RandomAccessFile(sName,"rw"); _xefFy
this.nPos = nPos; &KYPi'C9!z
oSavedFile.seek(nPos); n5DS
} x5(6U>-Y
*8bj3A]vf
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public synchronized int write(byte[] b,int nStart,int nLen) C09rgEB\B
{ /E39Z*
int n = -1; W ZT) LYA
try{ z/I\hC9i
oSavedFile.write(b,nStart,nLen); BXb=NE
n = nLen; j|KjQ'9
} Ol sX
catch(IOException e) &RHZ7T
{ -O^R~Q_`w
e.printStackTrace (); 4 Aj<k
} S}b^_+UbP
O**~ Tj
*mJ\Tzc)
return n; oj(st{,
} YNB7`:
i'QR-B&Z
F%:74.]Y
} I/*^s
O'Q,;s`uC
<}p]0iA
/* ]6 HR
**SiteInfoBean.java 9/`3=r@
*/ x*sDp3f[*
package NetFox; %a?\y_a=b
#tIeI6Qw
?Dl;DE1
public class SiteInfoBean { Yr*!T= z
HUChg{[
js9^~:Tw
private String sSiteURL; //Site's URL 8OMMV,QF
private String sFilePath; //Saved File's Path AtUtE#K
private String sFileName; //Saved File's Name e*yl_iW
private int nSplitter; //Count of Splited Downloading File bzr QQQ
gq]@*C
|)C #
public SiteInfoBean() I+F>^4_d
{//nSplitter的缺省值为5 4H^ACw
//default value of nSplitter is 5 1%C EUE
this("","","",5); w~q ]&
} 44s 9\
N4z[=b>
ilXKJJda
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *8_Dn}u?Jx
{ O+|ipw*B%
sSiteURL= sURL; C23p1%#1
sFilePath = sPath; 6<9}>Wkf
sFileName = sName; _#1EbvO*l
this.nSplitter = nSpiltter; 6oq5CDoq
PhPe7^
NJSbS<O
} (?g+.]Dt,
B9Mp3[
<CB%e!~.9
public String getSSiteURL() T`MM<+^G
{ P*B@it
return sSiteURL; Td|u-9OM
} g\?v 5
Lq$ig8V:O7
9Zj3"v+b
public void setSSiteURL(String value) $f _C~O
{ IdMwpru(
sSiteURL = value; %6%mf>Guf
} QVJpX;u
cWG%>.`5r
AE+BrN +"2
public String getSFilePath() OjAdY\ ]1
{ 8V}|(b#
return sFilePath; ke!
} OF={k[
sp:4b$zX
I]i( B+D
public void setSFilePath(String value) _WvVF*Q"k
{ &tvtL
sFilePath = value; -.y1]4
} ~;]kqYIJ
k7Qs#L
NiWAJ]Z
public String getSFileName() W7'<Jom|?
{ .)$MZyo
return sFileName; 9Bw#VQ
} _Y;tD
e ><0crb
r180vbN$
public void setSFileName(String value) ^\Z+Xq1~/
{ S<NK!89
sFileName = value; vpf.0!zh
} yyljyE
GC7WRA
YC8IwyL'
public int getNSplitter() @XolFOL"f"
{ Z#Kf%x.
return nSplitter; ,pI9=e@O/z
} ]vB\yQE
xSd&xwP
s5{=lP
public void setNSplitter(int nCount) Cs[d:T
{ G 3,v'D5
nSplitter = nCount; #+l`tj4b/
} ("t'XKP&N
} eK l;T
Nj3iZD|
Pb>/b\&JS
/* &l7E|.JE
**Utility.java cjPXrDl{\
*/ I/tMFg
package NetFox; 7~QI4'e
C 5gdvJN
Lu.+J]Rz
public class Utility { z/xPI)R[
f0sGE5
ceE]^X;p
public Utility() g assOd
{ lP`BKc,
=/46;844T
').)0;
} wxo
Kus=.(
//线程睡眠 T9Q3I
public static void sleep(int nSecond) 3r kcIVO
{ y0mNDze
try{ /9G72AD!
Thread.sleep(nSecond); n_km]~
} ( ~5M{Xh
catch(Exception e) kaekH*m~
{ j0mN4Ny
e.printStackTrace (); }psRgF
} Z)W8Of_
} PmE)FthdP(
7:u+cv
//日志 50N4J
public static void log(String sMsg) (~^fx\-S
{ zk8)!Af
System.err.println(sMsg); xrg?{*\
} v{a%TA9-
%DKFF4k
3MQZ)!6
public static void log(int sMsg) ~%/Rc`
{ \s5Uvws
System.err.println(sMsg); E:pk'G0bZ
} Bxm,?=h
} :uo1QavO@,
@=VxWU
QE(.w dHP
/* eTS}-
**TestMethod.java M@A3+v%K
*/ `3rwqcxA
package NetFox; SU~a()"
F(HfXY3
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public class TestMethod { h4pS~/
|qUGB.Q
2H|:/y
public TestMethod() BkB>eE1)Ea
{ ///xx/weblogic60b2_win.exe '9V/w[mI
try{ ]^~}/@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^ F]hW
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u<BU4c/p
SiteFileFetch fileFetch = new SiteFileFetch(bean); (gBKC]zvz3
fileFetch.start(); C 5.3[
} '8X>,un
catch(Exception e){e.printStackTrace ();} cJ96{+
uDDa>Ka#+
M5`v^>
} At(88(y-W
6Xvpk1
?gE=hh
public static void main(String[] args) K~ eak\=
{ d/7fJ8y8
new TestMethod(); Js,!G
} u;`]U$Qq9
} (u,)v_Oo]a
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