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)); l]R=I2t
} 4]G J+a
for(int i=0;i<nEndPos.length-1;i++) w#}[=jy
{ )[wB:kG
nEndPos = nStartPos[i+1]; QlE]OAdB42
} L0.F}~S
nEndPos[nEndPos.length-1] = nFileLength; *q;u%; 4
} q{Ao j
} k@Qd:I;;
4ibOVBG:*,
8Wba Hw_
//启动子线程 F/ o }5H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0@yw#.j
for(int i=0;i<nStartPos.length;i++) G,e!!J
{ ULH<FDot
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9CG&MvF c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^ 6b27_=
nStartPos,nEndPos,i); uA4xxY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %0Ibi
fileSplitterFetch.start(); !LM9
} ~^bf1W[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "^Vnnb:Z*o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #f@}$@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m*|G2
nEndPos = " + nFileLength); NY?pvb
// fileSplitterFetch[nPos.length-1].start(); \NZ@>on
LNcoTdv}k
{4{X`$
//等待子线程结束 Q[Gs%/>
//int count = 0; qnFg7X>C,
//是否结束while循环 (3WK2IM^
boolean breakWhile = false; %/2OP &1<
-HF1c
rn]F97v@]
while(!bStop) b#-=Dbe
{ tIk$4)ZAl
write_nPos(); JFdMYb
Utility.sleep(500); ?$MO!
breakWhile = true; Rrrq>{D
4-BrE&2f
rgo!t028^
for(int i=0;i<nStartPos.length;i++) j-d542"
{ woa|h"T
if(!fileSplitterFetch.bDownOver) 5 qMP u|A
{ 1HLU &
breakWhile = false; H#M;TjR
break; @1~cPt
} XVF!l>nE
} 5Y 7 %Z
if(breakWhile) m2HO .ljc
break; OaKr_m
tkQrxa|
!yvw5As%
//count++; Yfx?3
//if(count>4) drvz [ 9;
// siteStop(); HQSFl=Q
} ,#bT
^fV-m&F)K*
\E6 0
System.err.println("文件下载结束！"); {]%7-4E
} -Un"z6*
catch(Exception e){e.printStackTrace ();} uqVarRi$
} CDY3+!
3L-$+j~u
'Z|Czd8E
//获得文件长度 ^U);MH8
public long getFileSize() O;$}j:;KF
{ p0D@O_ :5
int nFileLength = -1; 8@ S@^C*F
try{ y7,t"XV
URL url = new URL(siteInfoBean.getSSiteURL()); L#WGOl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "EVf1iQ
httpConnection.setRequestProperty("User-Agent","NetFox"); '!`| H 3
9rIv-&7'm
ixL[(*V
int responseCode=httpConnection.getResponseCode(); TEla?N
if(responseCode>=400) ^x Z=";eq
{ PzT@q\O
processErrorCode(responseCode); --k!KrL
return -2; //-2 represent access is error :Dfl,=S
} x_9#:_S'
ltyhYPS
s)Xz}QPK.
String sHeader; ']d(m?
vsPIvW!V
S_ra8HY8
for(int i=1;;i++) !?sB=qo
{ >`|Wg@_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <?:h(IZe[
//Utility.log(in.readLine()); (1[Z#y[
sHeader=httpConnection.getHeaderFieldKey(i); <nK@+4EH"o
if(sHeader!=null) ~.#57g F"
{ _bRgr
if(sHeader.equals("Content-Length")) a5(9~.9
{ Z{gDEo)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |WNI[49
break; F$'po#
} KO/#t~
} -c{Y+M`
else '$VP\Gj.
break; [+ : zlA
} IR?nH`V
} >QPCYo<E
catch(IOException e){e.printStackTrace ();} ]bbP_n8
catch(Exception e){e.printStackTrace ();} 3NdO3-~)
$oJjgAxcZ
#bCUI*N"P
Utility.log(nFileLength); =@&>r5W1
s@g _F
7#N ?{3i
return nFileLength; "Xl"H/3r
} rHqP[[4B'
a@AIv"q
RjR+'<7E^
//保存下载信息（文件指针位置） E>:#{%
private void write_nPos() f%JM a]yV
{ =BbXSwv'(
try{ 8Pva]Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7jr+jNsowj
output.writeInt(nStartPos.length); hu7oJ H
for(int i=0;i<nStartPos.length;i++) 2@Q5Ta#h
{ +:Nz_l
// output.writeLong(nPos); |,({$TrF
output.writeLong(fileSplitterFetch.nStartPos); Y\ ;hjxR-
output.writeLong(fileSplitterFetch.nEndPos); sLzZ}u?(
} bM }zGFt
output.close(); 2IP<6l8N
} =$T[
catch(IOException e){e.printStackTrace ();} TH55@1W,[
catch(Exception e){e.printStackTrace ();} e.Q'l/g
} ;iQw2XhT
y-S23B(
\?|^w.
//读取保存的下载信息（文件指针位置） >>M7#hmt
private void read_nPos() yTNHM_P
{ IsVR4t]
try{ YS<KyTb"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }9N-2]
int nCount = input.readInt(); W"\+jHF"
nStartPos = new long[nCount]; of >
nEndPos = new long[nCount]; ma/<#l^}
for(int i=0;i<nStartPos.length;i++) r=xec@R]*
{ ys:F
nStartPos = input.readLong(); )`2ncb
nEndPos = input.readLong(); - ^Y\'y2
} :G=ol2Q
input.close(); e&K7n@
} r1z+yx
catch(IOException e){e.printStackTrace ();} m:k;?p:x
catch(Exception e){e.printStackTrace ();} *g9VI;X
} R:+?<U&
32pPeYxB!-
bxWzm|
private void processErrorCode(int nErrorCode) K.Cx 9
{ [#AI!-
System.err.println("Error Code : " + nErrorCode); 7\H_9o0$
} 1c*:" k
twt's,dO
WpMm%G~'4t
//停止文件下载 '5A&c(
public void siteStop() _bv9/#tR
{ z uo:yaO
bStop = true; B`vC>
for(int i=0;i<nStartPos.length;i++) @PK 1
fileSplitterFetch.splitterStop(); iQgr8[ SFf
+(`.pa z@
Gz--C(
} HcV,r,>e
} &o&}5Aba9
//负责部分文件的抓取 J<9}) m
**FileSplitterFetch.java #%/Jr 52<
*/ mi@uX@ #
package NetFox; iszVM
S2 P9C"
LaL{ ^wP
import java.io.*; rKTc6h:)
import java.net.*; f:AfMf>m
X|4Kdi.r@
B->oTC`5
public class FileSplitterFetch extends Thread { ]<9o>#3
kLXa1^Lq
J:IAs:e`
String sURL; //File URL A6xN6{R!
long nStartPos; //File Snippet Start Position tItI^]w2s
long nEndPos; //File Snippet End Position B"`86qc
int nThreadID; //Thread's ID d6zq,x!cI
boolean bDownOver = false; //Downing is over %][zn$aa|
boolean bStop = false; //Stop identical hn$jI5*`
FileAccessI fileAccessI = null; //File Access interface )/z+W[t
l{\k\Q!4
<!*O[0s
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @mcP-
{ =`!#V/=
this.sURL = sURL; \SWuylE
this.nStartPos = nStart; RGBntp%
this.nEndPos = nEnd; `2j"Z.=
nThreadID = id; 3qDuF
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D}2$n?~+
} <AHdz/N
v5FfxDvw
mAe)Hy %
public void run() \=(U tro
{ bE jQMlb
while(nStartPos < nEndPos && !bStop) bOr6"nn
{ hy3?.
I@1VX5
:Yi 4Ia
try{ "msPH<D
URL url = new URL(sURL); w-Q=oEt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R78P](1\>
httpConnection.setRequestProperty("User-Agent","NetFox"); !OOOc
String sProperty = "bytes="+nStartPos+"-"; /~g.j1g
httpConnection.setRequestProperty("RANGE",sProperty); d:hX3
Utility.log(sProperty); +('=RyoT
J|8 u
g{hbq[>X]
InputStream input = httpConnection.getInputStream(); D&6.> wt .
//logResponseHead(httpConnection); #* 8^ar<
kcP&''
.|y{1?f_
byte[] b = new byte[1024]; /f>I;z1
int nRead; ;v~xL!uQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) SPINV.
{ cdg&)
nStartPos += fileAccessI.write(b,0,nRead); b\xse2#
//if(nThreadID == 1) b^<7@tY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J& D0,cuk
} j^Ln\N]^
iUS?xKN$~-
F[X;A\
Utility.log("Thread " + nThreadID + " is over!"); ALKzR433/
bDownOver = true; >6'brb
//nPos = fileAccessI.write (b,0,nRead); f=>iiv
} V)mi1H|m
catch(Exception e){e.printStackTrace ();} T 0?9F2
} Pj7MR/AH
} 1+ V<-I@{
py\/m]
wNl "y
//打印回应的头信息 <7j"CcJzZ
public void logResponseHead(HttpURLConnection con) GJBMaT
{ K3`48,`?wA
for(int i=1;;i++) %:Zp7O2UB'
{ Lnl-han%
String header=con.getHeaderFieldKey(i); {HP.HK
if(header!=null) G+NTn\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7K/t>QrBtU
Utility.log(header+" : "+con.getHeaderField(header)); ?T>NvKF
else s)9sbJ
break; :(4];Va
} i6k~j%0m
} o H]FT{
.j`8E^7<
~0L:c&V
public void splitterStop() ^C{?LH/2
{ nyPW6VQ0n
bStop = true; W\z<pP
} uJJP<mDgA
DjiWg(X
=fI0q7]ndz
} !6*4^$i#o
q/3co86c
?WrL<?r)}U
/* inyS4tb
**FileAccess.java ?MJ5GVeH
*//文件访问(定位，写) w)Y}hlcq
package NetFox; >soSOJ[
import java.io.*; XQj+]-m
wKy4Ic+RV
P1"g62R
public class FileAccessI implements Serializable{ \6,Z<.I
^I!gteU;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t\lx*_lr
RandomAccessFile oSavedFile; 7 '7a`-W
long nPos; \3cg\Q+~
OLDEB.@
UG,n q
public FileAccessI() throws IOException {ALOs^_-
{ -V}ZbXJD
this("",0); &fifOF#[e
} [&{NgUgu"
_B\X&!G.
#M8>)oc
public FileAccessI(String sName,long nPos) throws IOException Jl89}Sf
{ &3Mps[u:h
oSavedFile = new RandomAccessFile(sName,"rw"); &sS]h|2Z5
this.nPos = nPos; Y\{lQMCy
oSavedFile.seek(nPos); 76S>xnN
} /S%!{;:
|r53>,oR<:
6 ZVD<C:\
public synchronized int write(byte[] b,int nStart,int nLen) |(R[5q
{ ZRCUM"R_
int n = -1; %l)~C%T
try{ r A9Rz^;xa
oSavedFile.write(b,nStart,nLen); z0 _/JwJn
n = nLen; zKaEh
} Redxg.P
catch(IOException e) ^s?i&K,!
{ {>.qo<k
e.printStackTrace (); XOJ@-^BX
} L&~>(/*7U
l,1.6
iTeFy-Ct
return n; 7R".$ p
} C,3yu,'
u9dL-Nr`
JPS<e*5
} \ffU15@N
|-VbJd
*wJ'Z4_5F
/* ij1g2^],4
**SiteInfoBean.java |}K7Q
*/ `H\NJ,
package NetFox; \fD[Ej
~7&O[
y1hJVYE2
public class SiteInfoBean { .(zZTyZr
7)au#K6
Cl3hpqv1I
private String sSiteURL; //Site's URL c)=UX_S!
private String sFilePath; //Saved File's Path [KwwhI@3
private String sFileName; //Saved File's Name QjwCY=PK!
private int nSplitter; //Count of Splited Downloading File {m<!-B95
@GE:<'_:{
0B~Q.tyP
public SiteInfoBean() @7<m.?A!
{//nSplitter的缺省值为5 >eaK@u-'0
//default value of nSplitter is 5 JZrUl^8E
this("","","",5); v4wXa:CJ
} UHUO9h
wenJ(0L|
%uhhQ<zs%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) RlTVx:
{ )ur&Mnmm
sSiteURL= sURL; zs@[!?A,
sFilePath = sPath; d@t3C8
sFileName = sName; $~*d.
this.nSplitter = nSpiltter; MHKB:t]hA
Gu9x4p
)d-{#
} EM.rO/qcW
uDi#a~m@
%uLyL4*L(p
public String getSSiteURL() 9CTvG zkw
{ A)q,VSR8
return sSiteURL; 4lfJc9J
} },LW@Z}
K1>(Fs$
Vl+,OBy
public void setSSiteURL(String value) cZXra(AD
{ 7%4@*
sSiteURL = value; 1 +'HKT}
} bwAL:
& A<Pf.Us
mF !=H%
public String getSFilePath() CiGN?1|
{ CVFsp>+
return sFilePath; ~cEr<mzR
} >K;'dB/m;1
MhpR^VM'.
q<cpU'-#
public void setSFilePath(String value) vXM``|
{ 3M&75OE
sFilePath = value; L&nGjC+Lr
} VCvqiHn
oWUDTio#[
{m%X\s;ni
public String getSFileName() XP-4=0zd
{ "ci<W_lx
return sFileName; 'Kj8X{BSFb
} oos35xV.
5&r2a}K
J;wA
public void setSFileName(String value) Ma3Hn
{ dj76YK
sFileName = value; 6gfdXVN5
} qqYH}%0dz
Up$vBE8i]
k]`3if5>
public int getNSplitter() []M+(8Z_P
{ Uq6..<#
return nSplitter; n[/|M
} %j=,c{`Q
7>m#Y'ppl@
+6{KrREX)
public void setNSplitter(int nCount) ngJES`0d
{ oB$D&
nSplitter = nCount; rkl/5z??
} |7I.DBjR;
} cZ7b$MZ%9
-j9R%+YW<
Q'^]lVY
/* -~h2^Oez
**Utility.java 6X:-Z3
*/ #|8!0]n'
package NetFox; Sk$XC
dR_hPBn/@
)N2yhdcqI
public class Utility { .n`MPx'
k>Qr14F
pDlh^?cux
public Utility() V@K}'f~
{ <_H0Q_/(
b`K~l'8
T+2I:W%
} ~4*9w3t
[M2,bc8SJV
//线程睡眠 p$@=N6)I.k
public static void sleep(int nSecond) GKPqBi[rO
{ /kVy#sT|
try{ ?lU]J]
Thread.sleep(nSecond); }~-)31e'`
} \'"q6y
catch(Exception e) -zz9k=q
{ ][bz5aV
e.printStackTrace (); _ #l b\
} );;UNO21+
} eeb8v:4
# dxlU/*
//日志 +.HQ+`8z]
public static void log(String sMsg) .?S#DS )
{ sa+:c{
System.err.println(sMsg); :"O=/p+*Us
} #D+Fq^="P
6M$.gX G.
Qq]UEI `Go
public static void log(int sMsg) '7'cKp
{ OG 5n9sx
System.err.println(sMsg); &TWO/F+Y
} !,\9,lc
} QbqLj>-AJ
:N)7SYQT
Zml9ndzT
/* Ed*`d>
**TestMethod.java [dU/;Sk5
*/ ~5}b$qL#`
package NetFox; =4JVUu~Z
T:.J9
n3b@6V1_
public class TestMethod { cX.v^9kuX
a/^YgrC\T
Punbw\9!d,
public TestMethod() PD/JXExK
{ ///xx/weblogic60b2_win.exe >cMU<'&
try{ A7_*zR@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l/rhA6kEU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cB<0~&
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;co{bk|rj
fileFetch.start(); D|-]"(2i
} 1<59)RiO>
catch(Exception e){e.printStackTrace ();} (%+DE4?
^QW%<X
R!pV`N
} &<^@/osi
!>S'eXt
`&9#!T.
public static void main(String[] args) V`fh,(:
{ J;_JHlK
new TestMethod(); nVyb B~.=
} 9'5,V{pj
} `8'T*KU
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