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)); 0*-nVC1
} G"._]3CPF
for(int i=0;i<nEndPos.length-1;i++) IX]K"hT
{ O"Ua|8
nEndPos = nStartPos[i+1]; y5AJ1A6?E
} w:~Y@b~D
nEndPos[nEndPos.length-1] = nFileLength; R:}u(N
} MlBw=Nr
} hExw}c
i9FtS7
C1YG=!
//启动子线程 Uq8=R)1<|d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; OYC\+ =
for(int i=0;i<nStartPos.length;i++) qp6*v&
{ Bt\z0*t=s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zLa3Q\T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Y3J;Kk#AH
nStartPos,nEndPos,i); 5?()o}VjAO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _=\=oC
fileSplitterFetch.start(); 3>I
} %j*i=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q:#Kt@W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |0jmOcZF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D" 4*&
nEndPos = " + nFileLength); 6uAo0+-k
// fileSplitterFetch[nPos.length-1].start(); OSsxO(;g
xn)eb#r
53w@
//等待子线程结束 U.[?1:v
//int count = 0; ?(!<m'jEy
//是否结束while循环 uDZ$'a
boolean breakWhile = false; x`#|8
nvdo|5
z U~o"Jv
while(!bStop) `S{Blv
{ MGmUgc
write_nPos(); u?>]C6$
Utility.sleep(500); -q-/0d<l
breakWhile = true; |4F3Gu
DG&[.dR+
d5x>kO'[l
for(int i=0;i<nStartPos.length;i++) 3N]
{ 8] BOq:
if(!fileSplitterFetch.bDownOver) J}035
{ L,XWX8
breakWhile = false; 0K&\5xXM
break; sZ,mRT
} +cw;a]o^>
} ( _{\tgSm
if(breakWhile) ':v@Pr|
break; 'Si1r%'m#
Z{|U!tn
KvM}g2"
//count++; O-M4NKl]6
//if(count>4) f8DF>]WW
// siteStop(); -cjwa-9 ~
} JERWz~n}
6L~tUe.G
W|PKcZ ]Uc
System.err.println("文件下载结束！"); LZCziW
} `W8A*
catch(Exception e){e.printStackTrace ();} l1RpG"
} =/k*w#j
}a(x L'F
;plzJ6>
//获得文件长度 |$r|DX1[
public long getFileSize() _%)v9}D
{ 0nF>E@j^[
int nFileLength = -1; dJhT}"x
try{ 3zO'=gwJ
URL url = new URL(siteInfoBean.getSSiteURL()); 4No!`O-!&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #K3A{ jb,
httpConnection.setRequestProperty("User-Agent","NetFox"); QES[/i +
y7I')}SC
JNzNK.E!m-
int responseCode=httpConnection.getResponseCode(); kq[*q-:"x
if(responseCode>=400) Z=sCYLm
{ zS*X9|p
processErrorCode(responseCode); {]\QUXH
return -2; //-2 represent access is error 3N?WpA768/
} Z6}B}5@y
M]?#]3XBNo
x}G["ZU}v]
String sHeader; =OIxG}*
T4`.rnzyRb
.[1"Med J
for(int i=1;;i++) ~M 6^%
{ 93|u. @lEy
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vjI>TIy
//Utility.log(in.readLine()); %f.(^<Gu
sHeader=httpConnection.getHeaderFieldKey(i); R{~Yh.)~
if(sHeader!=null) %3ecV$
{ A f@IsCOJ
if(sHeader.equals("Content-Length")) 3S-nsMs.
{ Gw6*0&3')
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .y{qsL^P
break; Vcg$H8m
} Be{7Rj v
} -Cxk#-sb#
else qlJP2Ig~
break; ;T!mNKl
} +*3\C!
} )TxAhaz+
catch(IOException e){e.printStackTrace ();} 00'R1q4
catch(Exception e){e.printStackTrace ();} M3j_sd'N
m'$]lf;*
H4 }^6><V
Utility.log(nFileLength); RsS?ibozl
3&kHAXzM
9g#L"T=
return nFileLength; 6R1){,8
} ~Rx[~a
X8Px
|1H"ya
//保存下载信息（文件指针位置） vV:eU-a
private void write_nPos() 08&DP^NS
{ r5z_{g
try{ *P&ZE
output = new DataOutputStream(new FileOutputStream(tmpFile)); K oPTY^
output.writeInt(nStartPos.length); 8Letpygm
for(int i=0;i<nStartPos.length;i++) ;2 oR?COW
{ +2=N#LM
// output.writeLong(nPos); 0[g8
output.writeLong(fileSplitterFetch.nStartPos); k/W$)b:Of`
output.writeLong(fileSplitterFetch.nEndPos); |HXI4MU"
} /"+n{*9
output.close(); m98j`t
} Q>u$tLX&
catch(IOException e){e.printStackTrace ();} QT/TZ:
catch(Exception e){e.printStackTrace ();} A,rgN;5fb
} U@dztX@u
ygr[5Tl
RuDn1h#u{
//读取保存的下载信息（文件指针位置） wE:hl
private void read_nPos() Af5O;v\
{ ,p/iN9+Z
try{ 't \:@-tQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .w^M?}dx
int nCount = input.readInt(); k.>*!l0
nStartPos = new long[nCount]; ce&)djC7U
nEndPos = new long[nCount]; j8?z@iG
for(int i=0;i<nStartPos.length;i++) ^EE3E'
{ RG|]Kt8
nStartPos = input.readLong(); $QmP' <
nEndPos = input.readLong(); vbzeabm
} *yOpMxE
input.close(); ,/{mRw%
} 2`/JT
catch(IOException e){e.printStackTrace ();} P9vN5|"M
catch(Exception e){e.printStackTrace ();} HJ]\VP9Zb
} 7%L%dyN
@47MJzC
utKtxLX"
private void processErrorCode(int nErrorCode) x F7C1g(
{ ]kx)/n-K
System.err.println("Error Code : " + nErrorCode); IF%^HK@
} I{AteL
:Eq=wbAw
>up'`K,
//停止文件下载 fQc2K|V
public void siteStop() J:Uf}!D
{ 48Y5ppcS
bStop = true; NJSzOL_
for(int i=0;i<nStartPos.length;i++) \ Xow#@[
fileSplitterFetch.splitterStop(); pUki!TA
c%c/mata?
C#[YDcp4
} |ZW%+AQ|
} SC)4u l%
//负责部分文件的抓取 l j*ELy
**FileSplitterFetch.java Lzu;"#pw
*/ EU.vw0}u8
package NetFox; _;",7bT80
$8h^R#
T1m'+^?"
import java.io.*; U.~,Bwb
import java.net.*; $Z(fPKRN/
gE%{#&*
rXXIpQRi$S
public class FileSplitterFetch extends Thread { 3UgusH3
U;o[>{L
YJ_`[LnL
String sURL; //File URL XH&Fn+
long nStartPos; //File Snippet Start Position [?VYxX@
long nEndPos; //File Snippet End Position }q9;..oL
int nThreadID; //Thread's ID !4d6wp"
boolean bDownOver = false; //Downing is over d)`XG cx{=
boolean bStop = false; //Stop identical ::Y
FileAccessI fileAccessI = null; //File Access interface vAiNOpz#
wP3_RA]z
c'?4*O
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException AEaT
{ iaBy/!i
this.sURL = sURL; e_s9E{(
this.nStartPos = nStart; ]bCeJE.+)
this.nEndPos = nEnd; 2T/C!^iJ)
nThreadID = id; B~oSKM%8R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =ZM#_uW
} Y,K): ~T
&P{
;K38I}
public void run() |1J=wp)#
{ xMJF1O?3
while(nStartPos < nEndPos && !bStop) X||Z>w}v
{ 5g ,u\`
Dt?O_Bdv[
qp (ng8%c
try{ R)?b\VK2$
URL url = new URL(sURL); U*F|Z4{W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xExy?5H7
httpConnection.setRequestProperty("User-Agent","NetFox"); ^ a%U *>P
String sProperty = "bytes="+nStartPos+"-"; |eL&hwqzG
httpConnection.setRequestProperty("RANGE",sProperty); B;tU+36nM
Utility.log(sProperty); Rro|P_
<y5V],-U
RP'`\||*
InputStream input = httpConnection.getInputStream(); :/fG %e
//logResponseHead(httpConnection); I$0JAy
^c{}G<U^
+4^XFPq~
byte[] b = new byte[1024]; cC w,b]
int nRead; ~d6_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'TpW-r:
{ |`T3H5X>
nStartPos += fileAccessI.write(b,0,nRead); K;;Q*NN-
//if(nThreadID == 1) Im%|9g;P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VpSk.WY/ e
} _ b}\h,Ky
):?ype>
Ls#pe
Utility.log("Thread " + nThreadID + " is over!"); 8}h ^Frh
bDownOver = true; 7r?O(0>
//nPos = fileAccessI.write (b,0,nRead); lM Gz"cym
} 6"Q/Y[y
catch(Exception e){e.printStackTrace ();} R-]QU`c
} ; iQ@wOL]
} 6~GaFmW=
],Wh]q
d$)'?Sf]h
//打印回应的头信息 g(<02t!OT=
public void logResponseHead(HttpURLConnection con) AWCzu5ve
{ Mh'QD)28c
for(int i=1;;i++) \@nmM&7C!4
{ B5Rmz&
String header=con.getHeaderFieldKey(i); pVn6>\xa
if(header!=null) I=&5mg=m
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,R0@`t1 p
Utility.log(header+" : "+con.getHeaderField(header)); Ou/@!Y1
else Q_/{TE/sO5
break; I^/Ugu
} -_'M *-
} *{tn/ro6a
o1"U'y-9V
h*)spwF-
public void splitterStop() Vi`+2%4
{ tp$NT.z
bStop = true; &J^@TgqL^
} R6dw#;6{I
K2nq2Gbn
z;1tJ
} Tz58@VYV
W5}.WFu
xXH%7%W'f
/* }aXc,;Ps
**FileAccess.java ZA>hN3fE'
*//文件访问(定位，写) ^mFuZ~g;?
package NetFox; lE08UEk1i
import java.io.*; `Q1T-H_
Eag->mw/~
2i', e
public class FileAccessI implements Serializable{ N::_JH?^=
h3aHCr E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7~cN
RandomAccessFile oSavedFile; IvetQ+
long nPos; ;E:ra_l
N<Rb<p%
8^p/?R^bu
public FileAccessI() throws IOException GhLgV
{ 3nd02:GF
this("",0); 82Nh;5Tr
} Ts:dnGR5
Nol',^)
4u X<sJ*
public FileAccessI(String sName,long nPos) throws IOException W>dS@;E
{ u)&6;A4
oSavedFile = new RandomAccessFile(sName,"rw"); =NAL*4c+
this.nPos = nPos; W6&".2
oSavedFile.seek(nPos); ~t<BZu
} !#3#}R.$Fl
&AGV0{NMh]
IyOujdKa
public synchronized int write(byte[] b,int nStart,int nLen) y_qFXd
{ #$K\:V+ 4
int n = -1; ~yt+xWV
try{ h_?D%b~5
oSavedFile.write(b,nStart,nLen); q{@>2AlK
n = nLen; PQ@(p%
} tAP~
catch(IOException e) W=mh*G3y
{ [@#P3g\:>W
e.printStackTrace (); r&0v,WSp&S
} r4Pm i
2aW&d=!ZV
3 _:yHwkD
return n; ff-9NvW4v
} tLS5yT/
HkJ$r<J2
lj@c"Yrk
} ff?:_q+.N
8NPt[*
l *yml
/* +_06{7@h
**SiteInfoBean.java Z)|*mJ
*/ \W(C=e
package NetFox; (Pin9^`ALc
rh${pHl
|6"zIHvtc
public class SiteInfoBean { 7tUl$H;I/R
A 99 .b
^&h|HO-5
private String sSiteURL; //Site's URL 4punJg~1
private String sFilePath; //Saved File's Path r?\hZ*|M
private String sFileName; //Saved File's Name dW,$yH_
private int nSplitter; //Count of Splited Downloading File _Wk!d3bsx
"npj%O<bd
87>\wUJ
public SiteInfoBean() lk%rE
{//nSplitter的缺省值为5 Hl?\P6
//default value of nSplitter is 5 $a(wM1S4
this("","","",5); 1;4TA}'H
} kJlRdt2
f<!eJO:<'
+ 3aAL&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (JL{X`gs#
{ $0AN5 |`g\
sSiteURL= sURL; *'QD!Tc
sFilePath = sPath; |B;:Ald
sFileName = sName; #Ji&.T^U/
this.nSplitter = nSpiltter; |TkMrj0
+smPR
x!tCK47Yq
} qI) Yzc/
7$\;G82_
R% l=NHB}
public String getSSiteURL() cmZ39pjBJ
{ A>bo Xcr
return sSiteURL; ,+oQ 5c(f
} bEMD2ABm
|jU/R
<I&X[Sqp
public void setSSiteURL(String value) z$QYl*F1
{ w=rh@S]
sSiteURL = value; f}Mc2PQ-
} A]WU*GL2H
/Pxt f~$
dK#:io[Nz
public String getSFilePath() G9 ;X=c
{ ) 'j7Ra
return sFilePath; ^}a..@|%W
} <KoiZ{V
^GD"aerNr
w+fsw@dK&
public void setSFilePath(String value) [W,Ej
{ [GyW1-p33w
sFilePath = value; *_}ft-*w
} K pDKIi
Q;*TnVbJ
#e}Q|pF
public String getSFileName() Ovxs+mQ
{ J2f}{!b+I
return sFileName; dzjp,c@
} (oBvpFP33
mp*&{[XoVC
XT9]+b8(M
public void setSFileName(String value) bX Q*d_]WT
{ C*a>B,H
sFileName = value; M2W4 RovfR
} `aD~\O
*P7 H=Yf&
UMILAoR
public int getNSplitter() &G\Vn,1v
{ <U%4$83$
return nSplitter; T`mG+"O
} J$F 1sy
v6uR[18
mEeD[dMN
public void setNSplitter(int nCount) s;Q0
{ `$*I%oT;
nSplitter = nCount; R}_B\#Q
} 9AF%Y:y
} !w2J*E\
io%WV%1_
mhVdsa
/* ,P ~jO
**Utility.java 1Bp?HyCR
*/ :%7y6V*
package NetFox; c|m*< i
`v?XFwnV`
Of0(.-Q w
public class Utility { VUnO&zV{
iga.B
G%ytp=N
public Utility() o|(Ivt7jk
{ ;O8'vp
w_qX~d/
o]/*YaB2>
} AK$&'t+$}7
Yw=7(}
//线程睡眠 g?B4b7II
public static void sleep(int nSecond) V3D`pt\[x
{ [GQn1ZLc
try{ lldNIL6B%
Thread.sleep(nSecond); Gk:tT1
} rf?%- X(V
catch(Exception e) v}\4/u
{ h'lqj0
e.printStackTrace (); R*0]*\C z
} 59Lc-JJ
} 8=!uQQ
\MqOHM.[
//日志 >PuQ{T I
public static void log(String sMsg) ^+p7\D/E(
{ ;n,xu0/
System.err.println(sMsg); :'`y}'
} U}T{r%9
r)S:-wP
B/O0 ~y!n
public static void log(int sMsg) L:j3
{ FYs]I0}|
System.err.println(sMsg); dJv2tVm&'
} @*Tql:Qcd^
} 9Js+*,t
&R5zt]4d&
"?%2`*\
/* Ie4\d2tQ;
**TestMethod.java :%_\!FvS
*/ +Jm~Um!
package NetFox; 1-V"uLy@gC
HmiG%1+{A
E/V_gci
public class TestMethod { ?wP/l
A^ofs*"Y
z~"Q_gme
public TestMethod() hCBre5
{ ///xx/weblogic60b2_win.exe N TcojA{V$
try{ gLm,;'h%u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ''dS{nQs
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); GQ(*k)'a
SiteFileFetch fileFetch = new SiteFileFetch(bean); {p.^E5&
fileFetch.start(); w_h{6Kc<
} 8eVy*h2:=
catch(Exception e){e.printStackTrace ();} P!Brw72
sZI"2[bk
i50E#+E8
} kXV;J$1
STl8h}C
JC0#pU;
public static void main(String[] args) b(oe^jeGz
{ C$p012D1
new TestMethod(); +e^CL#Gs
} 5vFM0
} $PG(>1e
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