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)); e[Vk+Te7
} bLWY Tj
for(int i=0;i<nEndPos.length-1;i++) #?\(l%
{ THy?Y
nEndPos = nStartPos[i+1]; uDJ;GD[yc
} E,ilJl\
nEndPos[nEndPos.length-1] = nFileLength; 2::YR?
} *MlEfmB(
} K@:omT
z3 ^_C`(F
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//启动子线程 _U LzA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o,?G(
for(int i=0;i<nStartPos.length;i++) 9iJ$M!
{ a6xo U;T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C6F7,v62
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Odw'Ua
nStartPos,nEndPos,i); Wj!+ E{y<r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *pD|N
fileSplitterFetch.start(); A4rMJ+!5
} %A3m%&(m&%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WB_BEh[>j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OXpN8Dh5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fD(r/~Vu
nEndPos = " + nFileLength); x%k@&d;z
// fileSplitterFetch[nPos.length-1].start(); PRUl-v
\}4*}Lr
D/"velV
//等待子线程结束 S"?fa)~
//int count = 0; rZ n@i
//是否结束while循环 F_-xp1|
boolean breakWhile = false; 8oI|Z=
/;}%E
J2 )h":2
while(!bStop) ?%~^PHgZ|
{ L#'XN H"
write_nPos(); v,*C>u\3s
Utility.sleep(500); g5pFr=NV
breakWhile = true; :JX2GRL4
.vy@uT,
8!.V`|@lt
for(int i=0;i<nStartPos.length;i++) |By[ev"Kh%
{ %,~\,+NP
if(!fileSplitterFetch.bDownOver) $mAC8a_Zu
{ iFI+W<QR
breakWhile = false; f@Jrbg
break; ?M|1'`!c8
} {irc~||4
} &b^~0Z
if(breakWhile) gjz-CY.hz
break; _()1"5{
g-UCvY I
hQY`7m>L
//count++; U$OI]Dd9
//if(count>4) 7FY2a
// siteStop(); K^@9\cl^
} @.i#uMWF`
OE0G*`m
'@@!lV
System.err.println("文件下载结束！"); $+n6V2^K)7
} g=t7YQq_~
catch(Exception e){e.printStackTrace ();} ^dk$6%0
} u_+iH$zA
u;t~ z
Z|x|8 !D
//获得文件长度 ,m]5j_< }
public long getFileSize() Bf#cBI
{ R3a}YwJFXF
int nFileLength = -1; -@_v@]:
try{ Q 318a0
URL url = new URL(siteInfoBean.getSSiteURL()); eBxm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E X'PRNB,
httpConnection.setRequestProperty("User-Agent","NetFox"); a9p:k ]{
! #! MTk
6YNL4HE?
int responseCode=httpConnection.getResponseCode(); qF`6l(
if(responseCode>=400) =z"+)N
{ jZkc yx
processErrorCode(responseCode); NNbdP;=:u
return -2; //-2 represent access is error %aw.o*@:
} gELG/6l
`?N0?;
m }HaJ
String sHeader; P33xt~
=c*l!."0
z#o''
for(int i=1;;i++) Y2 J-`o$5
{ @>VVB{1@,]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jy2gR1~
//Utility.log(in.readLine()); MA:5'n
sHeader=httpConnection.getHeaderFieldKey(i); /; Bmh=
if(sHeader!=null) UsFn!!+
{ o.fqJfpj
if(sHeader.equals("Content-Length")) m Rw0R{
{ ~I+MuI[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s^eiymP
break; =(7nl#o
} !*"fWahv
} T#3@r0M
else 0&]1s
break; zM=MFKhi ~
} UWKgf? _
} Rb0I7~Z%'d
catch(IOException e){e.printStackTrace ();} 0]
catch(Exception e){e.printStackTrace ();} oS..y($TI
io+V4m
1]~w?)..'
Utility.log(nFileLength); +Z|3[#W
u>:(MARsR
@ G)yz!H
return nFileLength; ;H~<.QW
} NvJ5[W
1F`jptVQ\G
Px=@Tw N,
//保存下载信息（文件指针位置） HVHv,:bPo
private void write_nPos() qJdlZW<
{ )'U0n`=
try{ A/'po_'uy
output = new DataOutputStream(new FileOutputStream(tmpFile)); ySmbX
output.writeInt(nStartPos.length); .nrllVG%`
for(int i=0;i<nStartPos.length;i++) v}Ju2}IK
{ rjK`t_(=
// output.writeLong(nPos); u7[}pf$}
output.writeLong(fileSplitterFetch.nStartPos); 4_=2|2Wz[
output.writeLong(fileSplitterFetch.nEndPos); w(6n
} <8^x Mjc
output.close(); k[ro[E
} ,.W7Z~z
catch(IOException e){e.printStackTrace ();} .M^[/!
catch(Exception e){e.printStackTrace ();} 8\lh'8
} ciS,
=zyA~}M2
BtC*]WB"_'
//读取保存的下载信息（文件指针位置） >UaQ7CRo
private void read_nPos() /gZyl|kdy
{ vNv!fkl
try{ !&rd#ZBn
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =,(TP
int nCount = input.readInt(); MY@&^71i4
nStartPos = new long[nCount]; a^p#M
nEndPos = new long[nCount]; yk`qF'4]
for(int i=0;i<nStartPos.length;i++) )e,O+w"
{ )?$[iu7 s
nStartPos = input.readLong(); Q# B0JT1
nEndPos = input.readLong(); 6UeYZ g
} R{H[< s+n
input.close(); e(?w h
} K@O^\
catch(IOException e){e.printStackTrace ();} 7pyzPc#_
catch(Exception e){e.printStackTrace ();} !=YKfzE
} fu^W# "{
BHUI1y5t
:dSda,!z
private void processErrorCode(int nErrorCode) ! ;t\lgMl
{ 2]5{Xmmo9
System.err.println("Error Code : " + nErrorCode); 8D*nU3O
} jb.H[n,\
-BSdrP|
Oo|PZ_P
//停止文件下载 Ur(R[*2bx
public void siteStop() r0XEB,}
{ Db,"Gl
bStop = true; -^xbd_'
for(int i=0;i<nStartPos.length;i++) @x}"aJgl
fileSplitterFetch.splitterStop(); kyJbV[o<#
"Wwu Ty|
DW. w=L|5R
} RSp wU;o6z
} .$18%jH#
//负责部分文件的抓取 q<dG}aj
**FileSplitterFetch.java *5%vU|9b
*/ nF,F#V8l
package NetFox; &<PIm
P]43FPb
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import java.io.*; e7RgA1
import java.net.*; K*>%,mP$i
VVas>/0qr
5qb93E"C
public class FileSplitterFetch extends Thread { $a M5jH<
f4"UI-8;n
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String sURL; //File URL UTD_rQ
long nStartPos; //File Snippet Start Position <q'l7S
long nEndPos; //File Snippet End Position {%R^8
int nThreadID; //Thread's ID *q=T1JY
boolean bDownOver = false; //Downing is over GJeG7xtJKl
boolean bStop = false; //Stop identical m4mE7Wn.3
FileAccessI fileAccessI = null; //File Access interface Q/+`9z+c
MuoE~K2
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QqA=QTZ}
{ v'W{+>.
this.sURL = sURL; lP F326e
this.nStartPos = nStart; i2,4:M)CV
this.nEndPos = nEnd; 1RRE{]2v#
nThreadID = id; VeYT[Us"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7IX8ck[D
} v>8C}d^
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public void run() >h\y1IrAaG
{ $DL}jH^S
while(nStartPos < nEndPos && !bStop) q[&Kr+)j
{ _K^Q]V[nZ
0bTj/0G?
s1:Wrz?4
try{ xyp{_ MZ
URL url = new URL(sURL); Bf utmI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oac)na:O#
httpConnection.setRequestProperty("User-Agent","NetFox"); *F\wWg'!B
String sProperty = "bytes="+nStartPos+"-"; n i#jAwkN5
httpConnection.setRequestProperty("RANGE",sProperty); 6"Uu;Q
Utility.log(sProperty); \^!;r9z=A
J9Ao*IW~
mZ+!8$1X
InputStream input = httpConnection.getInputStream(); @^{`!>Vt
//logResponseHead(httpConnection); Xs0)4U
mUBy*.
2q~.,vpP
byte[] b = new byte[1024]; PG&t~4QM`
int nRead; XF!L.'zH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JrzPDb`m
{ $.PRav
nStartPos += fileAccessI.write(b,0,nRead); RM;a]g*
//if(nThreadID == 1) g#5R||r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }"D;?$R!
} -?Cr&!*B
G:AA>t
5\Q Tm;
Utility.log("Thread " + nThreadID + " is over!"); p*;!5;OUR
bDownOver = true; 'nCVjO7o
//nPos = fileAccessI.write (b,0,nRead); d^C@5Pd <
} i,6OMB $
catch(Exception e){e.printStackTrace ();} %K6veB{M
} c1#0o)q*7
} Xw?DN*`L
nK>CPqB^(
YX$(Sc3.6
//打印回应的头信息 )~ (*q
public void logResponseHead(HttpURLConnection con) BEDkyz;:
{ yf&g\ke
for(int i=1;;i++) O^L]2BVC
{ i2=- su
String header=con.getHeaderFieldKey(i); pY31qhoZ.
if(header!=null) dGUP|O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0AQazhm
Utility.log(header+" : "+con.getHeaderField(header)); 6G8No-#y
else Rb6BY-/J
break; Pb5yz-?
} 9\Ii$Mp
} [LYO'-g^F#
F%w!I 9
,lZ19B?WP
public void splitterStop() eh86-tQI~(
{ CMj =4e
bStop = true; ,'8%'xit
} roADC?@r
%U\,IO`g
lw@Yn>eza
} 3&hR#;,"X
zp}7p~#k^
p<5]QV7st
/* Q((&Q?Vi
**FileAccess.java %*D=ni#(sT
*//文件访问(定位，写) Qit&cnO
package NetFox; `16'qc
import java.io.*; 1j?P$%p
Y~"tL(WfJl
^ja]e%w#
public class FileAccessI implements Serializable{ 2js/>L0
Ac:`xk<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 UqK.b}s
RandomAccessFile oSavedFile; ]s\r3I]
long nPos; CIW4E
};Q}C0E
*C_A(n5"V
public FileAccessI() throws IOException 7:4c\C0
{ 7`|'Om?'
this("",0); |Z:yd}d
} >Pw5!i\
kckRHbeU
,GSiSn
public FileAccessI(String sName,long nPos) throws IOException +( LH!\{^
{ #-L0.z(
oSavedFile = new RandomAccessFile(sName,"rw"); &~:EmLgv
this.nPos = nPos; de:@/-|
oSavedFile.seek(nPos); #Vk?
} "laf:Ty1
*AH`ob}
4|x_C-@
public synchronized int write(byte[] b,int nStart,int nLen) N:`_Vl
{ OyO<A3
int n = -1; /~,*DH$)
try{ Ao K9=F}
oSavedFile.write(b,nStart,nLen); $kUB%\`
n = nLen; P(aBJ*((~
} UC`h o%OBF
catch(IOException e) KL$.E!d
{ >|3Y+X
e.printStackTrace (); ?!RbS#QV}
} f^pBXz9&=
um9&f~M
]it. R-
return n; 7y Cf3
} hz/mNDE]
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G&oD;NY@/
} m` 1dB%;?
z^9oaoTl
[N,+mX
/* 7$*E0
**SiteInfoBean.java Tvv>9gS
*/ r_+Vb*|Y
package NetFox; =%U&$d|@G
"51/,D
6ALjM-t=V
public class SiteInfoBean { B- @bU@H
ag'hHFV
@`[e1KQ
private String sSiteURL; //Site's URL k$$SbStD
private String sFilePath; //Saved File's Path L?ZSfm2<
private String sFileName; //Saved File's Name kFjv'[Y1N
private int nSplitter; //Count of Splited Downloading File !oH{=.w
6 IvAs-%W
-6)nQNj|
public SiteInfoBean() 'Xik2PaO
{//nSplitter的缺省值为5 h,\{s_b
//default value of nSplitter is 5 -r*|N.5c
this("","","",5); [8'?G5/n
} -mO#HZIq
q^xG%YdPz+
"M/c0`>C!i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ';R]`vWFe
{ QGN+f)
sSiteURL= sURL; 2TGND-(j
sFilePath = sPath; -;cF)C--12
sFileName = sName; 0MRWx%CR
this.nSplitter = nSpiltter; !/G}vu
V7WL Gy.,
M6wH$!zRa
} 4q.;\n
_|e&zr
"|JbdI]%P
public String getSSiteURL() xoVd[c!
{ p&I>xu8fl
return sSiteURL; A.b^?k%I
} )j2#5`?"j
B W*8
& %/p;::A
public void setSSiteURL(String value) K~#?Y,}O
{ e6p3!)@P1
sSiteURL = value; sqhMnDn[
} M"*NV(".g
d'(n/9K
WWSycH ?[
public String getSFilePath() tQ@7cjq8bA
{ e (]]
return sFilePath; 3?D, Wu
} z#gebr~_\
{N]WVp*R
&en2t=a
public void setSFilePath(String value) }"+"nf5h
{ e/hCYoS1n
sFilePath = value; ObM/~{rKx
} {aA6b
<,$*(dX)(
!,ODczWvh
public String getSFileName() l^I?@{W
{ 7=G6ao7
return sFileName; }Bv1fbD4U
} o|>=<l
="]lN
|8E~C~d
public void setSFileName(String value) r.)n>
{ ]]y>d!
sFileName = value; 1tTP;C l#
} Foq3==*p
`XF[A8@h
XR",.3LD
public int getNSplitter() Pfs_tu
{ ,R=!ts[qi
return nSplitter; -W6@[5c
} sDs.da#*2
ac\aH#J_nC
^6# yL6E,~
public void setNSplitter(int nCount) R@grY:h
{ z~f;}`0
nSplitter = nCount; xJw" 8V<
} 64b AWHv
} 1PxRj
kKRu]0J~[
. AA# G
/* < e3] pM
**Utility.java L[PqEN\i
*/ )'jGf;du
package NetFox; M#Z^8(
E 1`g8Hk'
KT<i%)t2
public class Utility { ,X|FyO(p
@[joM*U
w}6~t\9D
public Utility() \>4>sCC
{ \X6q A-Ht
uxdB}H,
E`LaO
} 8oUR/___
De3;}]wC
//线程睡眠 c|:EMYS
public static void sleep(int nSecond) aNM*=y`
{ Q0`@=5?-
try{ }+lK'6
Thread.sleep(nSecond); \_u{ EB'b
} xBc$qjV
catch(Exception e) 2.JrLBhN
{ %o/@0.w
e.printStackTrace (); !!A(A^s
} iLQO .'{U
} dH0>lV
Jv 5l
//日志 aPe*@py3T
public static void log(String sMsg) O:+y/c
{ /(||9\;
System.err.println(sMsg); ^xk4HF
} ;s~xS*(C
ZwxEcs+UM
OWz{WV.
public static void log(int sMsg) p\I3fI0i
{ 44n41.Q]
System.err.println(sMsg); U1 3Lsky%
} A"DGn
} -mO<(wfV>
x-@?:P*
StR)O))I
/* T__@hfT
**TestMethod.java {|%^'lS
*/ P{s1NorKDh
package NetFox; PRYm1Y
Gyy4)dP
^4JK4+!Zfq
public class TestMethod { P5dD&
ve a$G~[%6
,]qc#KDq-1
public TestMethod() ?l[#d7IB
{ ///xx/weblogic60b2_win.exe rY&lx}
try{ 6_8yQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N1E9w:T`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); FME,W&_d
SiteFileFetch fileFetch = new SiteFileFetch(bean); {?w*n_T.
fileFetch.start(); ,: z]15fX
} VAheus
catch(Exception e){e.printStackTrace ();} _;BNWH
^eoW+OxH
R/B/|x
} }#g &l*P
7!o#pt7
D}{]5R
public static void main(String[] args) bA6^RIf?
{ x`p908S^
new TestMethod(); [N*S5^>1
} OvC@E]/+
} MD;,O3Ge
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