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)); X;0@41t'
} /:)4tIV
for(int i=0;i<nEndPos.length-1;i++) %|~UNP$
{ 6W o7q\"
nEndPos = nStartPos[i+1]; Hqk2W*UTl
} )sr]}S0
nEndPos[nEndPos.length-1] = nFileLength; Qy%/+9L
} qYs6PLC
} 1zffPC8jl
sQ$FtKm6
'_%Jw:4k
//启动子线程 6>Fw,$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6 9Cxh
for(int i=0;i<nStartPos.length;i++) P#C`/%$S
{ *Bj G3Jc5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B^Q#@[T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6lGL.m'Ra
nStartPos,nEndPos,i); (`N/1}vk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I <7K^j+5:
fileSplitterFetch.start(); jdzV&
} }\F>z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6)8']f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +}!eAMQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8MdKH7
nEndPos = " + nFileLength); c}lgWu~
// fileSplitterFetch[nPos.length-1].start(); >X]<s^
s?G@k}{
RDbA"e5x
//等待子线程结束 dK-G%5)r
//int count = 0; e-WaK0Ep
//是否结束while循环 )8_0d)
boolean breakWhile = false; 7g$t$cZby,
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mTt 9 o9E
while(!bStop) T &1sfS,
{ hH\(>4l
write_nPos(); `@90b4u
Utility.sleep(500); oj/tim
breakWhile = true; %2{E'^#)p-
LLMkv!%D
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for(int i=0;i<nStartPos.length;i++) sr\MQ?\fB
{ DmYm~hzJ
if(!fileSplitterFetch.bDownOver) pGC`HTo|
{ = 2k+/0ZbP
breakWhile = false; la-+`
break; otOl7XF
} Ldu!uihx
} N\u-8nE5
if(breakWhile) Kfi A 7W
break; cb+!H>+
R#t~i&v/
psMagzr&)e
//count++; 4xlsdq8`t
//if(count>4) _R]1J0
// siteStop(); FR&RIFy
} REw3>/=
>TE&myZ?*
biJU r^n
System.err.println("文件下载结束！"); `>V.}K^4
} ZE9*i}r
catch(Exception e){e.printStackTrace ();} /swTn1<Y
} Og["X0j
FvkKM+?F
DN!EsQ6
//获得文件长度 T]:5y_4?[
public long getFileSize() `s+qz
{ 6x{B
int nFileLength = -1; eRf8'-"#-
try{ +5Mx0s(5
URL url = new URL(siteInfoBean.getSSiteURL()); w9 NUm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y3thW@mD05
httpConnection.setRequestProperty("User-Agent","NetFox"); }>j$Wr_h
zIL.R#|D=
{3;4=R3
int responseCode=httpConnection.getResponseCode(); ScI9.{
if(responseCode>=400) %VdJ<=@
{ d+bTRnL
processErrorCode(responseCode); ZK;HW
return -2; //-2 represent access is error XhS<GF%
} OTRTa{TB
(<f[$ |%
N>/U%01a
String sHeader; wC[J=:]tA5
-0W;b"]+A
+n0y/0Au
for(int i=1;;i++) w<'mV^S
{ <"t >!I
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'd28YjtoX
//Utility.log(in.readLine()); rlds-j''
sHeader=httpConnection.getHeaderFieldKey(i); /q>"">
if(sHeader!=null) q[+];
{ #):FXB$a
if(sHeader.equals("Content-Length")) /g_}5s-Z
{ 6Us#4 v,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v(afaN
break; Fv3fad@x
} #R)$nv:h?^
} {C<ch@sR
else Q{>{ e3z}
break; A5z`3T;1
} Tx!mW-Lt
} K <0ItNv
catch(IOException e){e.printStackTrace ();} rUj]6j=e
catch(Exception e){e.printStackTrace ();} y:457R2F
L:S[QwQu8
<5nz:B/
Utility.log(nFileLength); mtHw!*
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* @oAM,@
return nFileLength; Oh|Hy/&6W
} 5T,`j=\
l9-(ofY*J
d`Wd"LJ=
//保存下载信息（文件指针位置） 1X=}
private void write_nPos() YpAjZQZ,
{ E*CY/F I_
try{ [Y5B$7|s<
output = new DataOutputStream(new FileOutputStream(tmpFile)); D@!#79:)
output.writeInt(nStartPos.length); 0"ZRJl<)[I
for(int i=0;i<nStartPos.length;i++) W#ev
{ VPf=LSxJe
// output.writeLong(nPos); HQ]g{JVld\
output.writeLong(fileSplitterFetch.nStartPos); 7ZN0_Qs
output.writeLong(fileSplitterFetch.nEndPos); !"_\5$5i<X
} fu33wz1$}B
output.close(); "*?^'(yA@
} h_H$+!Nzb
catch(IOException e){e.printStackTrace ();} TJ+yBMd*%
catch(Exception e){e.printStackTrace ();} 3C5<MxtK
} edA.Va|0
:dB6/@fW
ZXp=QH+f
//读取保存的下载信息（文件指针位置） V,lz}&3L
private void read_nPos() F(mm0:lT
{ )/Ul"QF
try{ c\7~_w2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0*x
int nCount = input.readInt(); 3PPN_Z
nStartPos = new long[nCount]; g&&5F>mF
nEndPos = new long[nCount]; {8'I+-
for(int i=0;i<nStartPos.length;i++) iFpJ/L
{ .]P@{T||Y
nStartPos = input.readLong(); }ufH![|[r
nEndPos = input.readLong(); rtC.!].;%
} iE>T5XV8$B
input.close(); TTu<~GH
} !@5B:n*
catch(IOException e){e.printStackTrace ();} EE-jU<>|
catch(Exception e){e.printStackTrace ();} ]Z6==+mCP
} E{|j
usX aT(K
F~4oPB K<
private void processErrorCode(int nErrorCode) BlMc<k
{ k\I+T~~xD
System.err.println("Error Code : " + nErrorCode); n-0RA~5z
} Q`'w)aV
g"^<LX-
6Xbo:#
//停止文件下载 $SA8$!:
public void siteStop() {p-&8-
{ ^pIT,|myY7
bStop = true; 7ZqC1
for(int i=0;i<nStartPos.length;i++) Ar,B7-F!
fileSplitterFetch.splitterStop(); kg1z"EE
@.@O#
UTC|8
} <S<@V?h
} XhhV7J_F
//负责部分文件的抓取 oYI7 .w
**FileSplitterFetch.java )w=ehjV^m
*/ *\L\Bzm
package NetFox; ncjtv"2R
z^'3f!:3
J{`G=
import java.io.*; ?@!dc6
import java.net.*; ]Vuq)#
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x(ue |UG
public class FileSplitterFetch extends Thread { ef*Vs
vu Vcv
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String sURL; //File URL N D`?T &PK
long nStartPos; //File Snippet Start Position Y`.FSs
long nEndPos; //File Snippet End Position B}Qpqa=_c
int nThreadID; //Thread's ID BUvE~l.,|
boolean bDownOver = false; //Downing is over $t}t'uJ
boolean bStop = false; //Stop identical __O@w.
FileAccessI fileAccessI = null; //File Access interface w7+3?'L
OXAr..
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _[SW89zk
{ W"MwpV
this.sURL = sURL; {$5?[KD
this.nStartPos = nStart; `v) :|Q
this.nEndPos = nEnd; }]VFLBl`w
nThreadID = id; dTcrJ|/Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C+tB$yahO
} RE6d&#N
]6#bp,
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public void run() wA$ JDf)Vg
{ jJc:%h$|2
while(nStartPos < nEndPos && !bStop) |soDt<y+L
{ V'alzw7#
S+9}W/
7.}Vvg#G
try{ s_:7dD
URL url = new URL(sURL); yUd>EnQna
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9 M>.9~
httpConnection.setRequestProperty("User-Agent","NetFox"); &![3{G"+>l
String sProperty = "bytes="+nStartPos+"-"; ^V,?n@c!
httpConnection.setRequestProperty("RANGE",sProperty); JiH^N!
Utility.log(sProperty); p^J=*jm)x
{B|)!_M#
u2\QhP 9
InputStream input = httpConnection.getInputStream(); apy9B6%PJ+
//logResponseHead(httpConnection); jAXKp b
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byte[] b = new byte[1024]; meJ%mY
int nRead; -,YoVB!T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |YEq<wbQ
{ xNAX)v3Z
nStartPos += fileAccessI.write(b,0,nRead); ~[a6
//if(nThreadID == 1) v_G1YC7TU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1xBgb/+
} GoSdo
f N_8HP6&
rD_\NgVAs
Utility.log("Thread " + nThreadID + " is over!"); 1/\JJ\
bDownOver = true; }%)]b*3
//nPos = fileAccessI.write (b,0,nRead); V$o]}|
} k7ye,_&>
catch(Exception e){e.printStackTrace ();} 9^+8b9y
} dBRK6hFC
} )wqG^yv
^L4"X~eM
Rq`d I~5!b
//打印回应的头信息 t nvCtuaR
public void logResponseHead(HttpURLConnection con) e)BU6m%
{ ~S\y)l\wZ
for(int i=1;;i++) y).dw(
{ ^]n:/kZ5"[
String header=con.getHeaderFieldKey(i); H"5=z7w
if(header!=null) \Dlmrke
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,uoK'_
Utility.log(header+" : "+con.getHeaderField(header)); -_[ZRf?^
else yor6h@F1
break; 3%~c\naD?O
} O n/q&h5
} 4(nwi[1Y
@h=r;N#/`P
i U"2uLgb
public void splitterStop() +Hd'*'c
{ ?Z(xu~^/
bStop = true; fug Fk
} Gg TrIF
7ILb&JQ!%{
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} 2]:Z7Ji
X+7@8)1(
Qo\+FkhYq
/* 1[:tiTG|C
**FileAccess.java rK~Obv
*//文件访问(定位，写) IeN~E'~
package NetFox; )=TS)C4
import java.io.*; j"5 $m@lgn
vX;~m7+
i+@t_pxc
public class FileAccessI implements Serializable{ D;! aix3
Q@(tyW+8U@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q ym=L(X
RandomAccessFile oSavedFile; $*$X5
long nPos; Eg+z(m$M
sI<PYi={-6
8[rZRc
public FileAccessI() throws IOException XMlcY;W
{ b|Sjh;
this("",0); ?v,4seRuz
} 9.>he+
Lj2Au_5
%X -G(Z
public FileAccessI(String sName,long nPos) throws IOException O>,Rsj!e
{ $N/"c$50,
oSavedFile = new RandomAccessFile(sName,"rw"); 5H!6m_,w
this.nPos = nPos; E}lNb
oSavedFile.seek(nPos); A}W}H;8x
} 6 K-jje;)
8~|tl,
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public synchronized int write(byte[] b,int nStart,int nLen) w%?6s3
{ ]I:h4hgw
int n = -1; 0eFvcH:qG
try{ I><sK-3
oSavedFile.write(b,nStart,nLen); Qm@v}pD
n = nLen; \1nj=ca?
} I*4g ;1x
catch(IOException e) fI }v}L^
{ dQ-:]T (
e.printStackTrace (); |Ye%HpTTv
} x.%x|6G*
"t&_!Rm
oi\e[qE
return n; ^3lEfI<pBm
} !Ct'H1J-
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' }T6dS
} wvz_)bN~A
cr>"LAi
R4AKp1Y
/* Sp\ 7
**SiteInfoBean.java {GhM,-%e
*/ d: LP8
package NetFox; &BE'~G
IRK(y*6
}0 b[/ZwQ
public class SiteInfoBean { ;oivG)hJl
V1 O]L66
E-i<^&E
private String sSiteURL; //Site's URL &uLC{Ik}
private String sFilePath; //Saved File's Path 7thB1cOJ
private String sFileName; //Saved File's Name 'eg;)e:`b+
private int nSplitter; //Count of Splited Downloading File w;]~2$
c=u'#|/eb
q%hxU.h
public SiteInfoBean() w<jlE8u
{//nSplitter的缺省值为5 @Rs3i;"W
//default value of nSplitter is 5 'w`3( ':=
this("","","",5); &k@r23V7r
} pa2cM%48
*,#T&M7D
U( (F<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Wer.VL
{ 'Ej&zh
sSiteURL= sURL; bFwc>
sFilePath = sPath; <,huajQs
sFileName = sName; 7#9yAS+x(
this.nSplitter = nSpiltter; uS&NRf9A
<}t<A
H-'~c\)
} I7} o>{
%bZ}vJ5b
<j&LC /]o
public String getSSiteURL() U`)o$4Bq
{ 3}V-'!
return sSiteURL; cRS2v--\-
} n81z0lnr
[O\[,E"K
E;Q ,{{#
public void setSSiteURL(String value) b&xlT+GN
{ HWxwG'EEY,
sSiteURL = value; \Ss6F]K]
} m6YDyQC
obtXtqew
xq\A TON
public String getSFilePath() Yxd&hr
{ 6R';[um?q
return sFilePath; ';Ew-u
} ylPDM7Ka
THf*<|
6U[bAp
public void setSFilePath(String value) L_QJS2
{ Av"^uevfs
sFilePath = value; EjFK zx
} 0pl |
4.qW ~W{
:8jaW?~
public String getSFileName() <imIgt|`2
{ JsyLWv@6xa
return sFileName; %:vMD
} QX>Pni
PHv0^l]B
fFNwmH-jv
public void setSFileName(String value) TF-k|##G
{ C">w3#M%
sFileName = value; a[A9(Ftn
} Y=YIz>u
<P#]U"?A
oY8S-N;(t
public int getNSplitter() 9~6)u=4sS"
{ N_eZz#);
return nSplitter; *g~\lFX,u
} GMJ</xG
\'.#of
NZ=`iA8)X
public void setNSplitter(int nCount) P/;d|M(
{ y;1l].L
nSplitter = nCount; 8e*1L:oB!
} v5`Q7ZZ
} CF_pIfbaf
Yk!TQY4
/ +9o?Kxya
/* Z+]Uw
**Utility.java SxWK@)tP
*/ [(PD2GO+
package NetFox; L2 ^-t7
wR*>9LjeG
6im!v<1Qx
public class Utility { ~T'Ri=
bL"!z"NA
Kb5 YA
public Utility() YH^h?s
{ mH\eJ
"JJEF2e@Z
@EV*QC2l;Y
} eSlZAdK
%jnSJjcq
//线程睡眠 csNB \
public static void sleep(int nSecond) ;Uv/#"r
{ yo@S.7[/
try{ '&n4W7
Thread.sleep(nSecond); 5}"@$.{i
} Q
catch(Exception e) 5y%-K=d
{ Hd9vS"TN]
e.printStackTrace (); [9>h! khs
} Od5I:p]N
} /n&Y6@W
/yn%0Wish
//日志 xhmrep6+<
public static void log(String sMsg) _)6N&u8
{ { i2QLS
System.err.println(sMsg); o2vBY]Tj
} !Ey=
^qP}/H[QT
4<{]_S6"0y
public static void log(int sMsg) c>3AR17+5
{ F#^<t$5t
System.err.println(sMsg); H@%Y"iIUP
} "x P2GZ
} t/`~(0F
H:jx_
{ICW"Rlcs
/* d?Y|w3lB
**TestMethod.java EBl?oN7E
*/ KqNbIw*sR
package NetFox; ]1k"'XG4,
jQIb :\0#
?5e]^H}
public class TestMethod { K,'v{wSr
r3_O?b
zXRq) ;s
public TestMethod() |{en){:
{ ///xx/weblogic60b2_win.exe FC BsC#
try{ o<Z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]:X# w0UR
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5y`n8. (?
SiteFileFetch fileFetch = new SiteFileFetch(bean); iE8
fileFetch.start(); f}C$!Lhs
} ccPTJ/%$
catch(Exception e){e.printStackTrace ();} 2@~hELkk/E
`\vqDWh8-
xS>d$)rIj
} 2uln)]
4,)EG1
O7of9F~"
public static void main(String[] args) {#o0vWS>
{ p6Ie?Gg
new TestMethod(); P56B~M_
} *@1(!A
} V@C8HTg
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