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)); &}oDSD H^,
} sgX~4W"J
for(int i=0;i<nEndPos.length-1;i++) K(?7E6\vO
{ TL5bX+
nEndPos = nStartPos[i+1]; #{(rOb6H)
} 711z-
nEndPos[nEndPos.length-1] = nFileLength; Ni`qU(I'|
} 1/ HofiIa
} JQb]mU%?
udB}`<Q
VC@o]t5
//启动子线程 eP)RP6ON{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "](~VF[J8
for(int i=0;i<nStartPos.length;i++) XxGm,A+>Ty
{ bFpwq#PDW>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rr*IIG&.5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E4{8 $:q=
nStartPos,nEndPos,i); \,WPFV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GM5::M]fS
fileSplitterFetch.start(); mxIEg?r(
} m{g{"=}YR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yC -4wn*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C-Mop,w
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xc!"?&\*
nEndPos = " + nFileLength); TM+7>a$
// fileSplitterFetch[nPos.length-1].start(); 8L#sg^1V
D`ZYF)[}J
r`=d4dK-
//等待子线程结束 mVxS[Gq
//int count = 0; )9*WmFc+#
//是否结束while循环 *]LM2J
boolean breakWhile = false; NH{0KZ R
30<^0J.1
bV"0}|A~K
while(!bStop) :KQ<rLd
{ uwbj`lpf
write_nPos(); 7"gy\_M
Utility.sleep(500); t((0]j^
breakWhile = true; vm(% u!_P
X/Ae-1!
:G!Kaa,r
for(int i=0;i<nStartPos.length;i++) lHx$F?
{ ]'"$qm:
if(!fileSplitterFetch.bDownOver) }&=C*5JN
{ fE(rDQI
breakWhile = false; ,QK>e;:Be
break; q|~9%Pujg
} N-^\e)ln
} qZ4DO*%b3
if(breakWhile) H)5]K9D
break; )T^hyi$
`8L7pbS%,Q
O@l`D`
//count++; Z@1rs#
//if(count>4) 3+)i23[4=\
// siteStop(); z=!xN5
} >Zr`9$i
?g!)[p`v
q|S }5
System.err.println("文件下载结束！"); =4?m>v,re
} J<'4(}^|
catch(Exception e){e.printStackTrace ();} [g<JP~4]
} /vBpRm
HxkhlNB
spJB6n(
//获得文件长度 ;lP)
public long getFileSize() 1:8ZS
{ "]sr4Jg=
int nFileLength = -1; IkD\YPL;
try{ .7oz
URL url = new URL(siteInfoBean.getSSiteURL()); [z?<'Tj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o0AREZ+I
httpConnection.setRequestProperty("User-Agent","NetFox"); rt f}4.
291v R]
<jxTI%'f59
int responseCode=httpConnection.getResponseCode(); Up8#Nz T
if(responseCode>=400) NKRNEq!
{ 5{{u #W%=
processErrorCode(responseCode); %KqXtc`O
return -2; //-2 represent access is error `*WR[c
} GR/ p%Y(
4-sUy
t; "o,T
String sHeader; 'l2`05
9Czc$fSSt
sI#K01;"
for(int i=1;;i++) cBU>/ zIp
{ F$d`Umqs;P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /']Gnt G.
//Utility.log(in.readLine()); ?L'ijzP
sHeader=httpConnection.getHeaderFieldKey(i); 2nk}'HBe
if(sHeader!=null) 0nBAO
{ zg[ksny
if(sHeader.equals("Content-Length")) d]CRvzW
{ pVLfZ?78
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )wmXicURC
break; XmLHZ,/
} )abo5
} f.Jz]WXw,
else wF}/7b54
break; y;uk|#qnPS
} w_6h $"^x
} !YCYmxw#
catch(IOException e){e.printStackTrace ();} L[D}pL=
catch(Exception e){e.printStackTrace ();} !x[+rf
D/rKqPp|!
{um~]
Utility.log(nFileLength); hmQD-E{Ab
dKhDO`.s
Y!}BmRLh2
return nFileLength; {R\"x|
} aabnlOVw
c/b}39X
BJ1txdxvS
//保存下载信息（文件指针位置） ^,@Rd\q
private void write_nPos() AS~O*(po
{ 4k}u`8 a
try{ S&FMFXF@
output = new DataOutputStream(new FileOutputStream(tmpFile)); `O-$qT,_
output.writeInt(nStartPos.length); @32JMS<
for(int i=0;i<nStartPos.length;i++) yPKeatH]
{ g?)9zJ9
// output.writeLong(nPos); S'lZ'H/
output.writeLong(fileSplitterFetch.nStartPos); YEQ}<\B\&
output.writeLong(fileSplitterFetch.nEndPos); [ q22?kT
} y1B3F5
output.close(); J1hc :I<;
} *o`bBdZ
catch(IOException e){e.printStackTrace ();} LsoP >vJG
catch(Exception e){e.printStackTrace ();} u<:RSg
} "4zTP!Ow
}"E?#&^
!Hxx6/
//读取保存的下载信息（文件指针位置） t /1KKEZM
private void read_nPos() }hhDJ_I5M
{ :voQ#f=
try{ :k#Y|(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }qRYXjS
int nCount = input.readInt(); uveTx
nStartPos = new long[nCount]; YOy/'Le^:
nEndPos = new long[nCount]; vaW,O/F
for(int i=0;i<nStartPos.length;i++) {a\m0Bw/
{ "xi)GH]H_
nStartPos = input.readLong(); KYZ/b8C
nEndPos = input.readLong(); ]W]o6uo7
} NN>,dd3T
input.close(); twq!@C
} glm29hF
catch(IOException e){e.printStackTrace ();} %[l5){:05
catch(Exception e){e.printStackTrace ();} b[%sKl
} =LC:1zn4
q",n:=PL
lo5,E(7~h
private void processErrorCode(int nErrorCode) $~75/
{ 'D;v>r
System.err.println("Error Code : " + nErrorCode); :dc>\kUIv
} #"|</*%>
<}&n}|!
IXDj;~GF
//停止文件下载 AQw1,tGV
public void siteStop() (Z fY/
{ }.>( [\q
bStop = true; @2nar<
for(int i=0;i<nStartPos.length;i++) g ]e^;
fileSplitterFetch.splitterStop(); YKlYo~fGN9
]6bh#N;.
+mIO*UQi
} v[E*K@6f
} m0DD|7}+
//负责部分文件的抓取 KmG*`Es
**FileSplitterFetch.java W1dpKv
*/ ycz6-kEp
package NetFox; )"`(+Ku&c
Dp3&@M"^yY
<lopk('7
import java.io.*; P-o/ax
import java.net.*; U-&dn%Sq
|3<tDq@+
W<_9*{|E;
public class FileSplitterFetch extends Thread { W$>srdG0$
aAhXHsZ|26
t6(LO9Qc
String sURL; //File URL [H<![Z1*r
long nStartPos; //File Snippet Start Position OGpy\0%
long nEndPos; //File Snippet End Position ">_<L.,I
int nThreadID; //Thread's ID % P .(L
boolean bDownOver = false; //Downing is over K%h9'}pq>1
boolean bStop = false; //Stop identical SaceIV%(
FileAccessI fileAccessI = null; //File Access interface V3r1|{Z(
lI~T>Lel2
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7}>Zq`]~
{ j}t"M|`
this.sURL = sURL; _IYd^c
this.nStartPos = nStart; T#KF@8'-
this.nEndPos = nEnd; `S$zwot
nThreadID = id; W6%\Zwav?)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #;~`+[y?\
} ?-C=_eZJ
g?&_5)&
1?%Q"*Y&
public void run() s&&8~ )H
{ 5-qk"@E W
while(nStartPos < nEndPos && !bStop) v<CZ.-r\j
{ &B?TX.
3>asl54
O=m_P}K
try{ 7~&
URL url = new URL(sURL); Qf|x]x*5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !8YZ;l
httpConnection.setRequestProperty("User-Agent","NetFox"); k@:M#?(F
String sProperty = "bytes="+nStartPos+"-"; Bu_/yKW
httpConnection.setRequestProperty("RANGE",sProperty); y.vYT{^
Utility.log(sProperty); M~/7thP{
R<(kiD\?]
{;mT.[
InputStream input = httpConnection.getInputStream(); t7#lRp&
//logResponseHead(httpConnection); r'*x><m'
3kqO5+,C
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byte[] b = new byte[1024]; Rn?Yz^ 1q
int nRead; 3lr9nBR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u*}[fQ`aF
{ ]6s7?07m4
nStartPos += fileAccessI.write(b,0,nRead); 8.JFQ/)i
//if(nThreadID == 1) $[(amj-;l
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 76 nrDE
} \EI<1B
J34/rL/s
3QSA|
Utility.log("Thread " + nThreadID + " is over!"); ,jH<i.2R
bDownOver = true; 3T1t !q4/5
//nPos = fileAccessI.write (b,0,nRead); m{#?fR=9
} ;|yd}q=p
catch(Exception e){e.printStackTrace ();} J n>3c
} P'}WmE'B}F
} 2:[ -
J:D{5sE<|
[7Fx#o=da
//打印回应的头信息 r{LrQ
public void logResponseHead(HttpURLConnection con) }`fFzb
{ 96ydcJY0'
for(int i=1;;i++) @~p;.=1]F
{ y-#{v.|L
String header=con.getHeaderFieldKey(i); k]>1@t
if(header!=null) WzinEo{f
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oz8z%*9(
Utility.log(header+" : "+con.getHeaderField(header)); #Sg< 9xsW
else [pY1\$,
break; dMd2a4
} b6(LoN.
} h95a61a,Vy
W0-KFo.'
9N[(f-`
public void splitterStop() "%zb>`1s
{ t@(:S6d
bStop = true; t_xO-fT)
} S"=y>.#
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3bsuE^,.@
} u B~C8}
)70i/%}7
reP)&Fo
/* VsU*yG a
**FileAccess.java o|en"?4
*//文件访问(定位，写) /E %^s3S.
package NetFox; g$/C-j4A[
import java.io.*; |7CFm
C(Cuk4K
tRZA`&
public class FileAccessI implements Serializable{ Qr.SPNUFK
Uf,fd
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l@W1bS
RandomAccessFile oSavedFile; *DDqa?gQb
long nPos; b}APD))*H!
HpKF7oJ'N
7jS`4,
public FileAccessI() throws IOException HuI?kLfj\
{ UwtLvd
this("",0); 5mqwNAv
} 'g5 Gdn
UG !+&ii|
90Sp(
public FileAccessI(String sName,long nPos) throws IOException [ !<
{ 0Z4o3r[
oSavedFile = new RandomAccessFile(sName,"rw"); w;p~|!
this.nPos = nPos; alp}p
oSavedFile.seek(nPos); P:OI]x4
} ).$q9G
,&F4|{
sx^0*h-Qq
public synchronized int write(byte[] b,int nStart,int nLen) -dyN Ah?=
{ x=I|O;"><
int n = -1; 5 (cgHr"
try{ 5>x?2rp
oSavedFile.write(b,nStart,nLen); ^yFtL(x,
n = nLen; Ze.\<^-t
} Vi*HG &DD
catch(IOException e) (3VV(18
{ ~PZIYG"D
e.printStackTrace (); AZH=r S`
} ]EWEW*'j
U(6=;+q
I xk+y?
return n; MszX9wl
} al1Nmc#
hk.vBbhs
o;"Phc.
} PdD,~N#
($T"m-e
elDt!9Pu
/* _&R lR
**SiteInfoBean.java #qDMUN*i
*/ (:r80:
package NetFox; %~rXJrK
MJ_]N+
)|N_Q}
public class SiteInfoBean { V`& O`
i"RBk%
g4f:K=5:
private String sSiteURL; //Site's URL o,gH*
private String sFilePath; //Saved File's Path e.'6q ($3
private String sFileName; //Saved File's Name -d)+G%{
private int nSplitter; //Count of Splited Downloading File p0sq{d~
o>jM4sk$
Ad)::9K?J
public SiteInfoBean() 6k+4R<
{//nSplitter的缺省值为5 "CY#_)
//default value of nSplitter is 5 Wi2Tg^
this("","","",5); > }fw7X
} Bm$(4
_^MkC}8
*LOUf7`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1+ib(MJ<:#
{ hM "6-60
sSiteURL= sURL; AI,Jy%62/
sFilePath = sPath; AD>X'J u8
sFileName = sName; zI{~;`tzN
this.nSplitter = nSpiltter; vE{L`,\q
$2/v8
]L/AW
} krMO<(x+
Ba#wW E
chakp!S=
public String getSSiteURL() k];NTALOG
{ )cV*cDL1j
return sSiteURL; sLze/D_M*
} kCHYLv3.
tl"?AQcBR
QzilivJf
public void setSSiteURL(String value) yFY:D2
{ l|j}Ggen
sSiteURL = value; yp?a7t M
} EWC{896,
uA;vW\fHr
C8W4~~1S
public String getSFilePath() 9D[Jn}E:
{ 73kU\ux
return sFilePath; 0WI@BSHnM
} HY2*5#T
7'zXf)!
NbPNcjPL
public void setSFilePath(String value) ^\Epz*cL
{ e1/{bX5
sFilePath = value; AU4K$hC^
} t.pn07$
z(eAhK}6?
AlA:MO]NM
public String getSFileName() f)19sjAJk
{ ~A@HW!*Z@
return sFileName; lPZYd8
} +x]3 -s
<`?V:};Q
qAW?\*n5N
public void setSFileName(String value) TD-o-*mO
{ EECuJ+T
sFileName = value; 2(i|n=
} ?k$'po*Eq
y8j6ttQv=t
RdqB^>X
public int getNSplitter() ac!!1lwA
{ YhQ%S}
return nSplitter; N;S1s0FN
} {1;R&
qO{Yr$V%
N4)ZPLV
public void setNSplitter(int nCount) *Xl,w2@
{ kp3%"i&hD
nSplitter = nCount; 3=-V!E
} K_ Odu^
} @p<tJR"M
]sZ! -q'8
Seh(G
/* ]Ns)fr6
**Utility.java > JV$EY,
*/ YL&)@h
package NetFox; Q!y%N&
`8/D$
J%FF@.)k
public class Utility { ;6M [d
K$KVm^`
lWakyCS
public Utility() {I8C&GS
{ W1_.wN$,5
x|$|~6f=n
4n} a%ocv^
} K05U>151
.'PS L
//线程睡眠 6d(D>a
public static void sleep(int nSecond) I8f='
{ C`=YGyj=TL
try{ U:0Ma6<
Thread.sleep(nSecond); ^*"i *e
} >%H(0G#X
catch(Exception e) 2b K1.BD
{ /B<QYvv
e.printStackTrace (); K%ptRj$
} SQDfDrYP
} rXR!jZ.hi
g OK
//日志 $`[TIyA9!
public static void log(String sMsg) d:pGdr& .
{ s_}`TejK
System.err.println(sMsg); cH6++r
} :-Ml?:0_X
[@_W-rA
{fJCj152.
public static void log(int sMsg) d7S?"JpV
{ &y&HxV
System.err.println(sMsg); r+k g$+%b
} [\qclW;L
} saTS8p z
^yX>^1
S,x';"
/* HR;I}J 9
**TestMethod.java _2TL>1KZt
*/ 1Qw_P('}
package NetFox; 55FRPNx-x
sC A
=Z ql6D
public class TestMethod { szCB}WY
dNf:I,<DCf
)|/%]@` N
public TestMethod() g`C\pdX"B
{ ///xx/weblogic60b2_win.exe V8#NXUg<!
try{ oFGWI#]ts>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >a&IFi,j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t.#ara{
SiteFileFetch fileFetch = new SiteFileFetch(bean); '<s54 Cb
fileFetch.start(); J0Gjo9L
} \CX6~
catch(Exception e){e.printStackTrace ();} adPd}rt;
L2=:Nac
( k,?)
} zdm2`D;~p
=*R6O,
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public static void main(String[] args) q~^!Ck+#*
{ j^%N:BQ&
new TestMethod(); \ef:H&r
} b:cy(6G(
} BOWOH
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