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)); Vdh5s292h
} G'#a&6
for(int i=0;i<nEndPos.length-1;i++) mWfzL'*
{ .y#@~H($
nEndPos = nStartPos[i+1]; maXQG&.F
} P0 hC4Sxf
nEndPos[nEndPos.length-1] = nFileLength; 6]CY[qEaR$
} 3' mQ=tKa
} pN1W|Wv2
)LKutN?tBy
m7~kRY514
//启动子线程 svHs&v
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; JY4 +MApN
for(int i=0;i<nStartPos.length;i++) C[|jJ9VE,
{ )zz"DH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -]A,SBs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F3;UH%L1
nStartPos,nEndPos,i); _~-VH&g0R
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j@&F[r
fileSplitterFetch.start(); cQA;Y!Q#
} Ro$l/lXl8t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "b|qyT* Sl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `G@]\)-!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?2aglj*"v,
nEndPos = " + nFileLength); _ ?xORzO
// fileSplitterFetch[nPos.length-1].start(); [?.k8;k
(wo.OH
3l-8TR
//等待子线程结束 6zaO$
//int count = 0; n]r7} 2hM
//是否结束while循环 "tn]s>iAd=
boolean breakWhile = false; > CZ|Vx
,_F1g<^@u
ri.;&
while(!bStop) &Plc
{ ![0\m2~iv
write_nPos(); Pz:,q~
Utility.sleep(500); !c[?$#W4
breakWhile = true; BwEO2a{
ovvR{MTc
!w(J]<
for(int i=0;i<nStartPos.length;i++) ?|w>."F
{ &)T5V
if(!fileSplitterFetch.bDownOver) {M)Y6\v
{ s%1O}X$c
breakWhile = false; )4toBDg"
break; wJNiw)C
} &&nvv&a
} ~*79rDs{
if(breakWhile) .Wc<(pfa
break; l#Ipo5=
.-awl1 W
(1^AzE%U+Z
//count++; -B*= V
//if(count>4) &'TZU"_
// siteStop(); 1~zzQ:jAZ
} 1I{vBeMj
*%=BcV+,
04D>h0yFf
System.err.println("文件下载结束！"); *:{s|18Pj
} wDVKp['
catch(Exception e){e.printStackTrace ();} .D!0$W mOZ
} nQy.?*X
jAie[5
M%92^;|`
//获得文件长度 3X=9$xw_
public long getFileSize() lmi,P-Q
{ LP-~;
int nFileLength = -1; %JF^@\E!|
try{ 4>-'wMW")
URL url = new URL(siteInfoBean.getSSiteURL()); >E;kM B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;4>YPH
httpConnection.setRequestProperty("User-Agent","NetFox"); U5\^[~vW
WXV(R,*Tc
Fku~'30
int responseCode=httpConnection.getResponseCode(); %UT5KYd!=N
if(responseCode>=400) zkt`7Pg;J
{ Z$LWZg
processErrorCode(responseCode); YcOPqvQ
return -2; //-2 represent access is error 2FU+o\1%
} rofj&{w
I$7|?8
#s>AiD
String sHeader; X6)%2TwO
Z}#'.y\ f
CT1@J-np
for(int i=1;;i++) >HNBTc=~t
{ = >CADTU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1yC_/Va1
//Utility.log(in.readLine()); : fMQ,S0
sHeader=httpConnection.getHeaderFieldKey(i); Kh&W\\K
if(sHeader!=null) w"ZngrwBl
{ IJa6W`}
if(sHeader.equals("Content-Length")) fIe';a
{ >M~1{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '2Q[g0VR
break; K)b@,/5
} \A7{kI
} M$_E:u&D
else kb3>q($
break; _E'F
} V6Z~#=EQ
} k;/K']4y
catch(IOException e){e.printStackTrace ();} bpP-wA^Hd
catch(Exception e){e.printStackTrace ();} IR JN
" GRR,7A
idsBw!DB
Utility.log(nFileLength); E$SYXe[,
}aO6%
e~oh%l^C72
return nFileLength; &s6;2G&L$
} abMB-
+pUG6.j%
`]~1pc
//保存下载信息（文件指针位置） dCA| )
private void write_nPos() I]GGmN
{ o8_))
try{ xVxN @[
output = new DataOutputStream(new FileOutputStream(tmpFile)); s>J\h
output.writeInt(nStartPos.length); \k4tYL5
for(int i=0;i<nStartPos.length;i++) LV2#w_^I
{ H(?)v.%
// output.writeLong(nPos); O06 2c)vIY
output.writeLong(fileSplitterFetch.nStartPos); H4B|c42
output.writeLong(fileSplitterFetch.nEndPos); J.;!l
} i%@blz:_Y
output.close(); W&~\@j]!D
} i~3\jD=<
catch(IOException e){e.printStackTrace ();} mH.c`*
catch(Exception e){e.printStackTrace ();} ,J6t 1V
} |j}D2q=
F8H4R7 8>;
3vXa#f>P<
//读取保存的下载信息（文件指针位置） |N5r_V
private void read_nPos() .;\uh$c
{ &?[g8A
try{ a = *'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2dsXG$-W2
int nCount = input.readInt(); MJ"@
nStartPos = new long[nCount]; :6gRoMb]
nEndPos = new long[nCount]; 'VpzB s#
for(int i=0;i<nStartPos.length;i++) g^l~AR
{ &]"Z x0t5%
nStartPos = input.readLong(); vh"wXu
nEndPos = input.readLong(); ayYl3
} *iX PG9XZ
input.close(); {x,d9I
} lvAKL>qX
catch(IOException e){e.printStackTrace ();} 3AcS$.G
catch(Exception e){e.printStackTrace ();} a B$x(8pP@
} mzRH:HgN?
)%q!XM
8vkCmV
private void processErrorCode(int nErrorCode) EtnuEU
{ 15z(hzU?#
System.err.println("Error Code : " + nErrorCode); S awf]/
} lY&Sx{-
P b-4$n2c
oeYUsnsbi
//停止文件下载 }}qY,@eeX
public void siteStop() (`&SV$m
{ |(<A)C
bStop = true; 2T?8{yO7
for(int i=0;i<nStartPos.length;i++) `@xnpA]l
fileSplitterFetch.splitterStop(); cG"wj$'w
b_&:tE--]
?[]jJ
} 0.\}D:x(z
} aX,6y1
//负责部分文件的抓取 .sjv"D"
**FileSplitterFetch.java {[4.<|26
*/ "!Qi$ ]
package NetFox; EK.n $
5g%D0_e5
$."DOZQ3U
import java.io.*; ov<vSc<u
import java.net.*; :HM~!7e
>Hu3Guik]
Aj8zFt]
public class FileSplitterFetch extends Thread { 2:@,~{`#*
s)jNP\-
2#
String sURL; //File URL AJ>$`=
long nStartPos; //File Snippet Start Position :-_"[:t 5Z
long nEndPos; //File Snippet End Position O]Ey@7 &
int nThreadID; //Thread's ID n&!q9CR`
boolean bDownOver = false; //Downing is over nA(5p?D+YB
boolean bStop = false; //Stop identical x~i\*Ox^
FileAccessI fileAccessI = null; //File Access interface K5RgWP
<*I*#WI&B
PMi.)%++
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7~r_nP_
{ ZA&bp{}D
this.sURL = sURL; VnqcpJ
this.nStartPos = nStart; Y(] W+k<
this.nEndPos = nEnd; !3<b#QAXRG
nThreadID = id; g*Pn_Yo[.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Lf:#koaC
} 2Jky,YLcb
F >H\F@Wl
>7)QdaB
public void run() D^xg2D
{ :]4s;q:m
while(nStartPos < nEndPos && !bStop) r:PYAb=g
{ 62kA(F0e,
Pc`)D:/}R
$> ;|
try{ nI4oQE
URL url = new URL(sURL); Ga+Cb2$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /3.;sS]B
httpConnection.setRequestProperty("User-Agent","NetFox"); OLWn0
String sProperty = "bytes="+nStartPos+"-"; |'lNR)5
httpConnection.setRequestProperty("RANGE",sProperty); D-D8La?0p
Utility.log(sProperty); AQtOTT$
v-8{mK`9\
S?zP; iFj
InputStream input = httpConnection.getInputStream(); I]HLWF
//logResponseHead(httpConnection); j >`FZKxp
$WE=u9m
+vH#xc\'
byte[] b = new byte[1024]; f'MRC \
int nRead; @=}NMoNH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y<~(}xsHh
{ c(29JZ
nStartPos += fileAccessI.write(b,0,nRead); :#\jx
//if(nThreadID == 1) JvEW0-B^l,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9=FH2|Z
} Zl>wWJ3y
V lkJ$f5l
dNCd-ep
Utility.log("Thread " + nThreadID + " is over!"); &xvNR=K[`
bDownOver = true; Pqj\vdzx
//nPos = fileAccessI.write (b,0,nRead); xb"e'Zh
} rLY I\
catch(Exception e){e.printStackTrace ();} l: kW|
} 5z_Kkf?o
} Ki1 zi~
*>!-t
1d842pt
//打印回应的头信息 UV</Nx)3
public void logResponseHead(HttpURLConnection con) 5!wjYQt3
{ !]9qQ7+R%
for(int i=1;;i++) ?=1i:h
{ i+Mg[x$.
String header=con.getHeaderFieldKey(i); *=]UWM~]
if(header!=null) 1vAJ(O{-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9.,IqnP
Utility.log(header+" : "+con.getHeaderField(header)); bdvpH DA
else [w-# !X2y
break; >L8 &6aU
} nEP3B'+
} rWqr-"0S.
"uj@!SEs`?
oA:`=f%\
public void splitterStop() FW)~e*@8=
{ In;P33'p
bStop = true; i7rk%q
} Ji1#>;&
' QjJ^3A
pcQkJF
} sk_xQo#Y 3
,1.Td=lY$
naA8RD5/
/* }IdkXAB.
**FileAccess.java ynf!1!4
*//文件访问(定位，写) 2|(lKFkQ
package NetFox; 0bD\`Jiv,
import java.io.*; bYX.4(R
}[PC YnS
t0?tXe.B
public class FileAccessI implements Serializable{ (dx~lMI
^; }Y ZBy
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {qU;>;(
RandomAccessFile oSavedFile; ><.*5q
long nPos; KdzV^6K<c
`Tk~?aY
*y` (^kyS
public FileAccessI() throws IOException ``@e7~F{
{ epG =)gd=8
this("",0); 2z AxGX
} /%F,
FF7?|V!Q
,Ij/ ^EC}
public FileAccessI(String sName,long nPos) throws IOException r gi4>
{ RSw;b.t7
oSavedFile = new RandomAccessFile(sName,"rw"); sXT8jLIf
this.nPos = nPos; - (q7"h
oSavedFile.seek(nPos); 5zyd;y)|'
} aZ|S$-}
&Z9rQH81f>
DK'S4%;Sp
public synchronized int write(byte[] b,int nStart,int nLen) Z Y5Pf 1
{ ^>eV}I5ak
int n = -1; ,w=u?
try{ cK\?wZ| Y
oSavedFile.write(b,nStart,nLen); )jjaY1E
n = nLen; o3NB3@uj<
} }I#_H
catch(IOException e) I*g[Y=
{ EN,}[^Z
e.printStackTrace (); >7cDfv"
} 3{Zd<JYg4-
10GU2a$0"$
ER}5`*X{
return n; rZ.z!10
} sheCwhV
dl`{:ZR S
znIS2{p/`
} n;:C{5
=+[`9
~at:\h4:
/* *_HF%JYMZ
**SiteInfoBean.java ZXIz.GFy+
*/ TQ%F\@"
package NetFox; uU-1;m#N?
Bo'v!bI7
vfc,{F=Q
public class SiteInfoBean { TZ}y%iU:mB
EN8xn9M?
#>sIXY
private String sSiteURL; //Site's URL i.KRw6
private String sFilePath; //Saved File's Path _kBx2>qQ
private String sFileName; //Saved File's Name ov >5+"q)
private int nSplitter; //Count of Splited Downloading File )@=fGNDt
yb0Mn*X+ N
SO<9?uk.
public SiteInfoBean() 2i NZz
{//nSplitter的缺省值为5 cJM.Q_I}Y
//default value of nSplitter is 5 T{=&>pNK[
this("","","",5); O.8k [Ht
} a(G}<
7?);wh7`
c'5ls7?}O{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {.e^1qE
{ PY&mLux%
sSiteURL= sURL; !;${2Q
sFilePath = sPath; gg Nvm
sFileName = sName; ;Sp/N4+
this.nSplitter = nSpiltter; 7*He 8G[W
\Xr*1DI<
o*oFCR]j
} k<NxI\s8]
K}'?#a(aX=
l 3 jlKB
public String getSSiteURL() Y_~otoSoY
{ +AFBTJ
return sSiteURL; FJT0lC
} %7?Z|'\
-D%mVe)&+
wyLyPJv
public void setSSiteURL(String value) BKgCuz:y
{ c: (nlYZ
sSiteURL = value; \m:('^\6o
} "^Y zHq6
Q8.LlE999
bL+}n8B
public String getSFilePath() Vjd>j; H
{ $\M];S=CY
return sFilePath; aP"!}*
} Wv~&Qh}
8NTE`l=>/
_>8Q{N\- {
public void setSFilePath(String value) 4U u`1gtz
{ ud"Kko Rt
sFilePath = value; o7eWL/1
} oY7jj=z#T
Iv*u#]{t
Yb1Q6[!
public String getSFileName() D_`NCnYG
{ Dv&K3^~Rfb
return sFileName; Sl@Ucc31
} !/=.~B
3e1P!^'\
C;.,+(G
public void setSFileName(String value) & x_ #zN]
{ ;mPX8bT
sFileName = value; 3Vak C
} ~R50-O
hVui.]
G.PRPl
public int getNSplitter() :+"H h%
{ e*U6^Xex
return nSplitter; xErb11
} 0sTR`Xk
7+qKA1t^
qwO@>wQ}~
public void setNSplitter(int nCount) mkl^2V13~
{ l,zhBnD
nSplitter = nCount; vhcp[=e :
} ]'-y-kqY
} e6^}XRyf
Q|e-)FS)
0N$FIw2
/* 1l Cr?
**Utility.java U]@?[+I0]
*/ m;t&P58f
package NetFox; $48Z>ij?f
+w"?q'SnF
ww #kc!'
public class Utility { =itQ@``r
_ElG&hyp
u8M_2r
public Utility() l5\V4
{ +T8MQ[(4
{^1''
;47z.i&T
} J0oeCb
P,F eF'J^
//线程睡眠 J_.cC
public static void sleep(int nSecond) 1:>F{g
{ "?<h,Hvi
try{ OA(.&5]
Thread.sleep(nSecond); O?cU6u;W
} lW|v_oP9
catch(Exception e) YPf?
{ y%spI/(
e.printStackTrace (); L"n)fe$
} 1hE{(onI
} Vu=/<;-N
~_c1h@
//日志 /,UnT(/k(
public static void log(String sMsg) DfP-(Lm)
{ qZ&~&f|>e
System.err.println(sMsg); `48Ql
} - l^3>!MAM
'tvuw\hhL
%OHZOs
public static void log(int sMsg) .T3 m%n
{ z|X6\8f
System.err.println(sMsg); RHMXPsj
} W5=)B`v
} i7e6lC
!8|}-eFY
Q2uV/M1?
/* Z7RBJK7|.
**TestMethod.java >%0$AW|Exu
*/ I[d<SHo
package NetFox; TlRc8r|
7.6L1srV
BP0:<vK{
public class TestMethod { g\ vT7x
+yHz7^6-5
3RT\G0?8f
public TestMethod() stBe ^C
{ ///xx/weblogic60b2_win.exe IA({RE
try{ lM{fld
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2wHbhW[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;}"Eqq:
SiteFileFetch fileFetch = new SiteFileFetch(bean); {svo!pN:
fileFetch.start(); )<:TpMdUk
} Y`Io}h G$
catch(Exception e){e.printStackTrace ();} G0Qw& mqF
IhYR4?e
ZcQu9XDIt
} _Uq' N0U
}Mt1C~{(
NX.xEW@
public static void main(String[] args) R]iV;j|
{ ~~Ezt*lH
new TestMethod(); ;ryNfP%
} (Y@T5-!D
} Xa?O)Bq.
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