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&6X|2@
} 8>Az<EF^=#
for(int i=0;i<nEndPos.length-1;i++) M,nX@8 _h
{ +ve S~
nEndPos = nStartPos[i+1]; }Fs;sfH
} s?r:McF`
nEndPos[nEndPos.length-1] = nFileLength; ,`kag~bZ
} cCOw7<
} jFS])",\i
HoE@t-S
5qZebD2a
//启动子线程 IkW8$>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R|4a9G
for(int i=0;i<nStartPos.length;i++) ]34fG3D|
{ C{Y0}ZrmlF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $=&a0O#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &!Sq6<!v2
nStartPos,nEndPos,i); }.`no
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jc8^m0_
fileSplitterFetch.start(); MPaF
} 3(?V!y{@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F_C7S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \mGx-g6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XR2Gw4]
nEndPos = " + nFileLength); `4GEq2%
// fileSplitterFetch[nPos.length-1].start(); .AHf]X0
sn>2dRW{
YCMXF#1
//等待子线程结束 4\?z^^
//int count = 0; >]/RlW[
//是否结束while循环 R_JB`HFy=
boolean breakWhile = false; LpV2XL$p>#
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zeqwmV=
while(!bStop) C0O$iWs=
{ Qk5pRoL_
write_nPos(); Jam&Rj,
Utility.sleep(500); P]A~:Lj
breakWhile = true; ?:$aX@r
z*oeho
,`Yx(4!rR
for(int i=0;i<nStartPos.length;i++) ZBY*C;[)*P
{ [}+h86:y
if(!fileSplitterFetch.bDownOver) 4lp90sa
{ Hoj'zY
breakWhile = false; qpEK36Js
break; u-/5&Endb
} |XrGf2P9u
} YqQAogyh
if(breakWhile) S\poa:D`
break; 8MZ:=
.Ce0yAl~
j9sLR
//count++; S%6V(L|
//if(count>4) yDORL| E'
// siteStop(); xoB "hNIX
} 6uu49x_^L4
l0&U7gr
)b=m|A GX
System.err.println("文件下载结束！"); =XhxD<kI
} Qd"R@+i
catch(Exception e){e.printStackTrace ();} cT.8&EEW
} Y$4dqn
C"cBlru8B
e_h`x+\:
//获得文件长度 KB`">zq$u
public long getFileSize() *7`amF-
{ @wTRoMHPQ
int nFileLength = -1; ;kLp}CqV
try{ f1wwx|b%.
URL url = new URL(siteInfoBean.getSSiteURL()); aSMSuX8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q6T>y%|FZ
httpConnection.setRequestProperty("User-Agent","NetFox"); !4"<:tSO
FNHJHuTe
ApotRr$)
int responseCode=httpConnection.getResponseCode(); '(fCi
if(responseCode>=400) 15Vo_ wD<y
{ ]%<0V,G q
processErrorCode(responseCode); PESJ7/^E
return -2; //-2 represent access is error _>/OqYR_jQ
} [h@MA|
?t"bF:!
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String sHeader; Jh`6@d
W<OO:B.ty
E|BiK
for(int i=1;;i++) Sp~gY]:
{ A]%hM_5s
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zmpQ=%/H
//Utility.log(in.readLine()); I3D#wXW
sHeader=httpConnection.getHeaderFieldKey(i); *+>R^\uT
if(sHeader!=null) v}^ f8nVR
{ qkh.?~
if(sHeader.equals("Content-Length")) M$AQZ')9
{ *l\vqgv.Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &Vi0.o
break; n+;PfQ|
} Q=cbHDB
} bcy( ?(
else 2z=GKV
break; &m>txzo
} ?$\y0lHw/7
} p!w}hB598
catch(IOException e){e.printStackTrace ();} n\D3EP<s
catch(Exception e){e.printStackTrace ();} ?FRQ!R
!B\[Q$
dwt<s[k
Utility.log(nFileLength); q{t"=@lX01
@5-+>\Hd^t
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return nFileLength; 59I}
} R(sa.Q\D4
8!AMRE
xuDn:
//保存下载信息（文件指针位置） PX1Scvi
private void write_nPos() Ev\kq>2O
{ 7F{=bL
try{ tKUy&]T
output = new DataOutputStream(new FileOutputStream(tmpFile)); V6ioQx=K#
output.writeInt(nStartPos.length); Eh)VU_D
for(int i=0;i<nStartPos.length;i++) m'%Z53&
{ OWK)4[HY(
// output.writeLong(nPos); m 5NF)eL
output.writeLong(fileSplitterFetch.nStartPos); IBzHXa>75
output.writeLong(fileSplitterFetch.nEndPos); sE8.,\
} m&Mvb[
output.close(); r4xq%hy
} 1% )M-io
catch(IOException e){e.printStackTrace ();} #:68}f"$
catch(Exception e){e.printStackTrace ();} 0OMyE9jJJ
} b+M[DwPw
DOWUnJ;5
G\H@lFh
//读取保存的下载信息（文件指针位置） vN7ihe[C
private void read_nPos() ma }Y\(38
{ MQ>vHapr
try{ #U&G$E`7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 'eo2a&S2D
int nCount = input.readInt(); cQv*lvG9>
nStartPos = new long[nCount]; Z3R..vy8
nEndPos = new long[nCount]; pKMf#)qm
for(int i=0;i<nStartPos.length;i++) kx1-.~)p(z
{ o\Hg2^YY>
nStartPos = input.readLong(); |l ~BdP
nEndPos = input.readLong(); A}\Rms2
} 3a{QkVeV7
input.close(); 'EREut,>'
} kozg8 `\]
catch(IOException e){e.printStackTrace ();} M14_w,
catch(Exception e){e.printStackTrace ();} 7B%@f9g
} eS@RA2
fV}\
8XJ%Yuu
private void processErrorCode(int nErrorCode) i%*x7zjY{
{ h)wR[N]n
System.err.println("Error Code : " + nErrorCode); CsSB'+&{
} +d6E)~qKL
CaBTqo
GN1cnM>`
//停止文件下载 {b<8Z*4W
public void siteStop() :` ~b&Oz)
{ q]Qgg
bStop = true; h'-TZXs0e1
for(int i=0;i<nStartPos.length;i++) o3WkbMJWM
fileSplitterFetch.splitterStop(); &`TX4b^/!
Tz*5;y%4
x(b&r g.-0
} >uuX<\cW
} s\jLIrG8
//负责部分文件的抓取 u8<=FV3
**FileSplitterFetch.java p[o2F5 T2
*/ ^5T{x>Lj
package NetFox; XPEjMm'*b3
WJ.PPq>]F
Q49|,ou[H
import java.io.*; &erNVD5o
import java.net.*; B)-S@.u
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lpp'.HTP
public class FileSplitterFetch extends Thread { GS{9MGl
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]52_p[hZ}<
String sURL; //File URL 8D n]`}ok
long nStartPos; //File Snippet Start Position 2)8lJXM$L
long nEndPos; //File Snippet End Position MYx*W7X
int nThreadID; //Thread's ID (~OwO_|3
boolean bDownOver = false; //Downing is over x9ws@=[:
boolean bStop = false; //Stop identical wk/->Rz
FileAccessI fileAccessI = null; //File Access interface cu"%>>,,
=_1" d$S&
2~@=ua[|=5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException l1:j/[B=
{ @!MbPS
this.sURL = sURL; @1+/r?b
this.nStartPos = nStart; ?SAi tQ3
this.nEndPos = nEnd; =['ijD4TW
nThreadID = id; xl9l>k6,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dg!sRm1iZ:
} oD8-I^
wLO/2V}/
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public void run() B%pvk.`
{ ]@P*&FRcZ
while(nStartPos < nEndPos && !bStop) 5R Hs
{ =,'Z6?%p
lrE0)B5F
g3Q #B7A
try{ JU@$(
URL url = new URL(sURL); (NQ[AypMI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tWiV0PTI
httpConnection.setRequestProperty("User-Agent","NetFox"); c5;ROnTm
String sProperty = "bytes="+nStartPos+"-"; P2p^jm
httpConnection.setRequestProperty("RANGE",sProperty); dF,FH-
Utility.log(sProperty); }B-A*TI<h
qWFg~s#+
v(^rq
InputStream input = httpConnection.getInputStream(); fUXp)0O
//logResponseHead(httpConnection); Rv-o__C!
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_:L*{=N
byte[] b = new byte[1024]; zi ,Rk.
int nRead; K9q~Vf
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <@A^C$g
{ 3$8}%?i
nStartPos += fileAccessI.write(b,0,nRead); XbC8t &Q],
//if(nThreadID == 1) O5Lv:qAa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WI6E3,ejB1
} bwJi[xF
o zYI/b^
mSfhl(<L
Utility.log("Thread " + nThreadID + " is over!"); 1Tq$E[
bDownOver = true; Ic K=E]p
//nPos = fileAccessI.write (b,0,nRead); qt(:bEr^6b
} cPcV[6)5K9
catch(Exception e){e.printStackTrace ();} F47n_JV!d
} _kHpM:;.
} 6bNW1]rD
^wa9zs2s;/
L{f>;[FR
//打印回应的头信息 >~rd5xlk
public void logResponseHead(HttpURLConnection con) 0*?XQV@
{ s8[9YfuW
for(int i=1;;i++) fWyDWU
{ /8}+#h)[
String header=con.getHeaderFieldKey(i); x\.i`ukx
if(header!=null) EcoUpiL%2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?(q*U!=
Utility.log(header+" : "+con.getHeaderField(header)); 4i/q^;`
else $`{q[{
break; 51qIo4$
} i\;&CzC:
} `^L<db^A
H?j-=Zka
(Dm"e`
public void splitterStop() I`W-RWZ
{ yvWzc uL#
bStop = true; Gv,92ny!|
} o U}t'WU
V-;nj,.mY
v*~%x
} #IaBl?}r^
_8li4;F
d]ZC8<`w
/* d50IAa^p6J
**FileAccess.java ru/zLj:
*//文件访问(定位，写) /P!X4~sTM
package NetFox; 9Ir~X|}\iL
import java.io.*; t+!gzZ
df4^C->:
jaO#><f
public class FileAccessI implements Serializable{ \e:FmG
0|s$vqc
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QE#-A@c
RandomAccessFile oSavedFile; VIz{}_~'s
long nPos; ;8L+_YCa
i[ Gw7'f
DtF![0w/
public FileAccessI() throws IOException }`9fZK{. @
{ 1Fvv/Tj
this("",0); QVSsi j
} "`jZ(+
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7:VEM;[d
public FileAccessI(String sName,long nPos) throws IOException ilIV}8
{ \9>g;qPg}
oSavedFile = new RandomAccessFile(sName,"rw"); J"D&q
this.nPos = nPos; b#Fk>j
oSavedFile.seek(nPos); PK-}Ldj
} nz&b5Xb2
o]|oAN9
VRd:2uDS
public synchronized int write(byte[] b,int nStart,int nLen) DV7<n&P
{ (!_X:+0_
int n = -1; sxN>+v11z
try{ ~51kiQW
oSavedFile.write(b,nStart,nLen); xS H6n
n = nLen; aR="5{en{:
} X|-v0 f
catch(IOException e) \]f5
{ >%n8W>^^4
e.printStackTrace (); qXP1Q3
} M]6w^\4j9
'FPcAW^8
fXF=F,!t
return n; fw1;i
} |z!q r}i
*c~'0|r
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} hkmTpH1<M
@b::6n/u
2_oK5*j
/* <t?x 'r?@
**SiteInfoBean.java a<57(Sf
*/ ;uM34^
package NetFox; J+/}K>2#
$n=W2WJ6f
++Rdv0~
public class SiteInfoBean { T=eT^?v
b[J-ja.
26\HV
private String sSiteURL; //Site's URL ESC
private String sFilePath; //Saved File's Path RJtixuvh@
private String sFileName; //Saved File's Name `YFkY^T
private int nSplitter; //Count of Splited Downloading File sowbg<D
\S=XIf
>Jm-2W5J
public SiteInfoBean() T!m42EvIvE
{//nSplitter的缺省值为5 ~I8v5 H
//default value of nSplitter is 5 3n.+_jQ>s
this("","","",5); i>ESEmb-
} c0!Te'?
hrJ$%U
g>6:CG"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [b7it2`dl
{ uHfhRc9
sSiteURL= sURL; E0sbU<11
sFilePath = sPath; pj!k|F9
sFileName = sName; tpv?`(DDU
this.nSplitter = nSpiltter; ]sX7%3P
z{_mEE49
2"T8^r|U
} DWF >b
'4J&Gpx
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public String getSSiteURL() \1=T sU&^
{ bcq@N
return sSiteURL; mcvDxjk,h
} }R`8h&J
ot-(4Y
bZxv/\
public void setSSiteURL(String value) qsI{ b<n
{ ^bF}_CSE
sSiteURL = value; ceqFQ
} t@X M /=d
\V._Z>]
dz8-):
public String getSFilePath() x*:n4FZ7b
{ +nU',E
return sFilePath; )$MS 0[?
} RI?NB6U
;_x2Ymw
Y3D3.T6Q
public void setSFilePath(String value) |p;4dL
{ b21}49bHN
sFilePath = value; QxKAXq@)i
} x<8\-
SO7(K5H,
X88F>1}
public String getSFileName() @v"T~6M
{ TV<Aj"xw
return sFileName; c qv.dC
} XnD0eua#
Pv#KmSA9
fQxSMPWB
public void setSFileName(String value) *8/VSs
{ Lg8]dBXu
sFileName = value; d"Bo8`_
} :#qUMiu$
'HCnB]1
5qGGu.$Ihi
public int getNSplitter() fTTm$,f5N
{ S3;lKr
return nSplitter; 9wzwY[{
} iL+y(]
4AJ9`1d4
'\@WN]
public void setNSplitter(int nCount) |%-YuD
{ R!9qQn?
nSplitter = nCount; ^+EMZFjg(
} D_Guc8*
} @$Yb#$/
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[~t yDLC
/* R<>tDwsZGa
**Utility.java vpi l$Uq
*/ rJX\6{V!_
package NetFox; lz- iCZ
GZ <nXU>
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public class Utility { L(;.n>/
>C:If0S4X
p x0Sy|
public Utility() }Iip+URG
{ `wf|uM
$Vsy%gA<
y>)MAzz~\
} }{A?PHV5
?@>;/@
//线程睡眠 9Eu #lV
public static void sleep(int nSecond) 6A.P6DW
{ !8o\.uyi
try{ F'rt>YvF
Thread.sleep(nSecond); ",T`\8&@e
} lf6|.
catch(Exception e) loBtd%wY
{ vkuc8 li
e.printStackTrace (); b#A(*a_gN
} #%4=)M>^
} gd_^
8!;$qVt
//日志 Ox~ 9_d
public static void log(String sMsg) D,E$_0
{ =tnTdp0F
System.err.println(sMsg); Ww=O=c5uOu
} e$32
i+1Qf
&>g~-s
public static void log(int sMsg) g#|oif9o
{ (![t_r0
System.err.println(sMsg); R5gado
} 0U%Xm[:
} i%MA"I\9
@+:4J_N
%Ci^*zb
/* Q-(Dk?z{
**TestMethod.java guE2THnz3D
*/ <ZVZ$ZW~D
package NetFox; #)`\!)?
Dp`HeSKU^
`R0Y+#$8h
public class TestMethod { 5j`v`[B;
z&>|*C.Y
[IMQIX
public TestMethod() V_f`0\[x
{ ///xx/weblogic60b2_win.exe GG+5/hU
try{ T/NjNEd#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \lW_f{X)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l])Q.m
SiteFileFetch fileFetch = new SiteFileFetch(bean); vK:QX$b
fileFetch.start(); tt{`\1q
} R6<4"?*r
catch(Exception e){e.printStackTrace ();} 5VKcV&D
s1=+::
HCazwX
} M~p=#V1D
r)8z#W>s
s7"i.A
public static void main(String[] args) (u9Zk~)F
{ 7E~4)k0<
new TestMethod(); mW +tV1XjG
} ;UpJ=?W
} UJn/s;$.e
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