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)); .Ys e/oEo
} &%J{uRp
for(int i=0;i<nEndPos.length-1;i++) , ['}9:f9
{ 4U2{1aN`
nEndPos = nStartPos[i+1]; .AN1Yt
} Y9BQLu4F
nEndPos[nEndPos.length-1] = nFileLength; 8W3zrnc
} 5OM#_.p
} le*+(aw
eKLvBa-{@
}6Pbjm*
//启动子线程 AA\)BNM
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <B@NSj
for(int i=0;i<nStartPos.length;i++) sY<UJlDKT
{ ~[=<Os
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S1|5+PPs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6R :hsC$
nStartPos,nEndPos,i); w!lk&7Q7Z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zJXK:/
fileSplitterFetch.start(); 2poo@]M/
} }u#3hYa
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Jp jHbG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L|1,/h 8p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,#;hI{E
nEndPos = " + nFileLength); MkW=sD_
// fileSplitterFetch[nPos.length-1].start(); %??v?M*
Gf8^nfr
2: QT`e&
//等待子线程结束 MKbcJZe
//int count = 0; 628iN%[-
//是否结束while循环 NV5qF/<M
boolean breakWhile = false; cGm3LS6]*
eEXNEgbn
cB&_':F
while(!bStop) yPE3Awh5
{ U\%r33L )
write_nPos(); RUY7Y?
Utility.sleep(500); O=__w *<
breakWhile = true; ")KqPD6k
*iB&tWv
eb7UA=[Z
for(int i=0;i<nStartPos.length;i++) 3cHYe
{ hh4R
if(!fileSplitterFetch.bDownOver) a!R*O3
{ L9jT:2F
breakWhile = false; ]9_gbQ
break; ILr=<j
} 1;[KBYUH
} +cfcr*
if(breakWhile) ]QlW{J
break; *I :c@iCNJ
pZ8J\4+
G:*vV#K
//count++; OROvy
//if(count>4) $e1.y b%
// siteStop(); !4Aj#`)
} 7R:j^"I@
ezw*Lo!
LqYyIbsvf
System.err.println("文件下载结束！"); YM`T"`f
} S ,F[74K
catch(Exception e){e.printStackTrace ();} fTXip)n!r
} P;"moluE;
@Ommd{0M
# fqrZ9:@
//获得文件长度 8XJi}YPQ
public long getFileSize() 1j<uFhi>
{ J2}poNmm
int nFileLength = -1; ^EiU>
try{ =F|9ac9X
URL url = new URL(siteInfoBean.getSSiteURL()); j-d&4,a:c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \^6[^\@[
httpConnection.setRequestProperty("User-Agent","NetFox"); 2|x !~e.
%GTFub0F
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int responseCode=httpConnection.getResponseCode(); SY|K9$M^
if(responseCode>=400) eL~xS: VT
{ 'IY?=#xr'`
processErrorCode(responseCode); \ Bj{.jL
return -2; //-2 represent access is error e1g3a1tnWl
} /4O))}TX
WowT!0$
M(L6PyEa!Y
String sHeader; # bHkI~
!p$p 7
_<RTes
for(int i=1;;i++) I?Iz5e-
{ ?L\"qz%gP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6=n|Ha
//Utility.log(in.readLine()); 0g30nr)
sHeader=httpConnection.getHeaderFieldKey(i); f I=G>[
if(sHeader!=null) dwk%!%
{ hZfj$|<
if(sHeader.equals("Content-Length")) ]y.V#,6e
{ (o*YGYC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7d R?70Sz
break; d4ecF%R
} Nl[&rZ-&
} S3/%;=|
else 1J0gjO)AZ
break; /?r A|
} l<XYDb~op
} ntLEk fK{
catch(IOException e){e.printStackTrace ();} 8\68NG6o
catch(Exception e){e.printStackTrace ();} H?O5 "4a
6!>p<p"Ns
?fH1?Z\'K
Utility.log(nFileLength); cO7ii~&%!
@\nQ{\^;
:+6W%B
return nFileLength; q83^?0WD
} ]=t}8H
u `/V1
+rU{-`dy9'
//保存下载信息（文件指针位置） IDn<5#
private void write_nPos() ;4!H- qZ
{ MlYm\x8{M
try{ (1|wM+)"
output = new DataOutputStream(new FileOutputStream(tmpFile)); `bBkPH}M
output.writeInt(nStartPos.length); \}4Y]xjV2
for(int i=0;i<nStartPos.length;i++) YIwa =^
{ 0?$|F0U"J
// output.writeLong(nPos); r'Wf4p^Xd
output.writeLong(fileSplitterFetch.nStartPos); ke8g tbm
output.writeLong(fileSplitterFetch.nEndPos); -XXsob}/8
} .KKecdd?=
output.close(); x?o#}:S
} RAl/p9\A+
catch(IOException e){e.printStackTrace ();} xI{fd1
catch(Exception e){e.printStackTrace ();} R_B0CM<!
} 27N;>
)qb'tZz/g_
a%.W9=h=M(
//读取保存的下载信息（文件指针位置） 0e<>2AL
private void read_nPos() s8&q8r7%
{ ~2\Sn-`
try{ 8<"g&+T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Xgd-^
int nCount = input.readInt(); joskKik^
nStartPos = new long[nCount]; MoN0w.V
nEndPos = new long[nCount]; lGr=I-=
for(int i=0;i<nStartPos.length;i++) @Pk<3.S0
{ B>c$AS\5y
nStartPos = input.readLong(); m6[}KkW
nEndPos = input.readLong(); ,V,mz?d^9
} H2%Qu<Kg2
input.close(); *VhEl7
} OY}FtGy
catch(IOException e){e.printStackTrace ();} ,2$<Pt;
catch(Exception e){e.printStackTrace ();} lND2Kb
} OC*28)
z |llf7:
O Ol:
private void processErrorCode(int nErrorCode) `2]0 X#R
{ V3ht:>c9qs
System.err.println("Error Code : " + nErrorCode); 1v|-+p42
} s>o#Ob@4'
2, )>F"R
*gH]R*Q[Rt
//停止文件下载 pDlrK&;\z
public void siteStop() z*h:Nt%.
{ )>{.t=#
bStop = true; te(H6c#0
for(int i=0;i<nStartPos.length;i++) }},0#Ap
fileSplitterFetch.splitterStop(); Rm=p}
hUi@T}aA|
uKAI->"
} <~5O-.G]
} F:q4cfL6
//负责部分文件的抓取 NH|I>vyN
**FileSplitterFetch.java AwNr}9`
*/ zQulPU
package NetFox; Zpg;hj5_
\"(?k>]E
,i6E L
import java.io.*; e:Y+-C5
import java.net.*; 0\:=KIY.
<z\SKR[
]TT >3"Dw7
public class FileSplitterFetch extends Thread { ,5v'hG
=xm7i#1
U\Vg&"P
String sURL; //File URL @ &N
long nStartPos; //File Snippet Start Position A]!0Z:{h%
long nEndPos; //File Snippet End Position N\*oL*[j
int nThreadID; //Thread's ID <b H*f w
boolean bDownOver = false; //Downing is over ,e43m=KhK
boolean bStop = false; //Stop identical A .&c>{B7
FileAccessI fileAccessI = null; //File Access interface RJ@79L*#
?)-6~p 4N
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :W0p36"
{ *|Vf1R]
this.sURL = sURL; :ZY%-]u7
this.nStartPos = nStart; 4&cQW)
this.nEndPos = nEnd; )nO ^Ay
nThreadID = id; b_RO%L:"yL
fileAccessI = new FileAccessI(sName,nStartPos);//定位 neM.M)0
} c`;oV-f
~'lT8 n_
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public void run() G/p\MzDko
{ ={%'tv`
while(nStartPos < nEndPos && !bStop) LH(P<k&
{ B`e/ /
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fX`u"`o5
try{ AuQ|CXG-\
URL url = new URL(sURL); _y[C52,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R 9`[C
httpConnection.setRequestProperty("User-Agent","NetFox"); se %#U40*
String sProperty = "bytes="+nStartPos+"-"; xR0*w7YE
httpConnection.setRequestProperty("RANGE",sProperty); V8 8u-
Utility.log(sProperty); &zF>5@fM
n#x_da-m]
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InputStream input = httpConnection.getInputStream(); U!q2bF<@
//logResponseHead(httpConnection); "O>~osj
e2c'Wab
MS;^:t1`
byte[] b = new byte[1024]; }d}gb`Du
int nRead; 'O)v@p "
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c qCNk
{ ):PN0.H8
nStartPos += fileAccessI.write(b,0,nRead); %cn1d>M+I
//if(nThreadID == 1) 8_!qoW@B
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,nYa+e
} ?I^$35
Bbs1U
w3,KqF
Utility.log("Thread " + nThreadID + " is over!"); )1Bz0:
bDownOver = true; C`[2B0
//nPos = fileAccessI.write (b,0,nRead); >KuNHuHu
} n~6$CQ5dF(
catch(Exception e){e.printStackTrace ();} -lJ|x>PG'
} A^,ul>!
} ,JdBVt
HDKF>S_S
EM@|^47$
//打印回应的头信息 0bh 6ay4
public void logResponseHead(HttpURLConnection con) THq}>QI
{ -Ct+W;2
for(int i=1;;i++) |_p7vl"
{ T3oFgzoO
String header=con.getHeaderFieldKey(i); :epBd3f
if(header!=null) A[m?^vk q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); YaS!YrpI
Utility.log(header+" : "+con.getHeaderField(header)); Ne+Rs+~4
else \m|5Aqs
break; vxPE=!|
} it H
} (Z>?\iNJ
mh"PAp
o=Z:0Ukl]
public void splitterStop() VQ('ejv}/
{ 3y.+03 W
bStop = true; k?7"r4Vc)S
} EwzcB\m
3\Xk)a_
}Y7P2W+4?
} _qPKdGoM
h!dij^bD
17'd~-lE
/* ~s&r.6DW
**FileAccess.java t+A*Ws*o
*//文件访问(定位，写) ^ulgZ2BQ|
package NetFox; $MgO)bH
import java.io.*; MRz f#o<H
I@m(}
$)*qoV
public class FileAccessI implements Serializable{ }OIe!
?cWwt~N9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :7X4VHw/
RandomAccessFile oSavedFile; RDSC@3%
long nPos; l7T?Yx j
[@qjy*5p
$A~aNI
public FileAccessI() throws IOException -`5]%.E&8
{ xT&/xZLT
this("",0); |s/Kb]t
} r(wf>w3
40=u/\/K
\1<aBgKi
public FileAccessI(String sName,long nPos) throws IOException cPZ\iGy
{ U~BR8]=G
oSavedFile = new RandomAccessFile(sName,"rw"); wq.'8Y~BE
this.nPos = nPos; 0B1nk!F
oSavedFile.seek(nPos); =,it`8;
} 92Gfxld\
uy2~<)
-,*m\Fe}
public synchronized int write(byte[] b,int nStart,int nLen) DW,ERQ^
{ {w3<dfJ
int n = -1; J;XO1}9
try{ kJB:=iq/x$
oSavedFile.write(b,nStart,nLen); .7 j#F
n = nLen; ZL0Vx6Ph
} 38-kl,Vw
catch(IOException e) @>VX]Qe^X
{ 5I[:.o0
e.printStackTrace (); }#.OJub
} e%:vLE 9
|^Yz*r?BJ
D@X"1X!F`G
return n; ;C=d( pY
} k {{eyC
? .B t.
T*B`8P
} 'S}3lsIE
hB<(~L?A]
ghW`xm87
/* rg[#(
**SiteInfoBean.java +Goh`!$Rj9
*/ ])qnPoQ<n
package NetFox; 4J'0k<5S
3`D*AFQc
Vq#0MY)2gS
public class SiteInfoBean { a"4X7 D+
21<Sfsc$
C+!=C{@7di
private String sSiteURL; //Site's URL Y[b08{/
private String sFilePath; //Saved File's Path .(p_YjIA
private String sFileName; //Saved File's Name P;XA|`&
private int nSplitter; //Count of Splited Downloading File kn$SG
Ot=nKdP}D
{gEz;:!):
public SiteInfoBean() f[NxqNn
{//nSplitter的缺省值为5 G?~Yw'R^8
//default value of nSplitter is 5 Q>X1 :Zn3
this("","","",5); pdN8hJ
} zO9WqP_`iR
DI-&P3iGx
oEZhKVyc.y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J7WNgl% u
{ zvnd@y{[
sSiteURL= sURL; /!5cf;kl*l
sFilePath = sPath; m_ wvi
sFileName = sName; oP7)
this.nSplitter = nSpiltter; _o?aO C
t#f-3zd9
w"kBAi&
} X/%!p<}:'
:zIB3nT^
JC$_Pg!
public String getSSiteURL() g]MgT-C|
{ |LZ+_
return sSiteURL; M?sTz@tqq
} .pxUO3g
FS)C<T]t
8rBa}v9
public void setSSiteURL(String value) &-IkM%_A9
{ NU.4_cixb
sSiteURL = value; 'T|QG@q
} P_Gu~B!Y
d@ZXCiA},
H2g#'SK@
public String getSFilePath() {P?p*2J'
{ Hjs#p{t[
return sFilePath; btC<>(kl&
} uu0t}3l
M_$;"NS+}
j~in%|^
public void setSFilePath(String value) [p0_I7
{ 6m(+X MS
sFilePath = value; %,8 "cM`D
} 9QF,ynE
s}gdi
W+V &
public String getSFileName() qpf|.m
{ Sng3B
return sFileName; /sB,)>X
} l,QO+ >)z
5@bmm]
;;^?vS
public void setSFileName(String value) D_z&G)
{ Y!u">M#@
sFileName = value; N4yQ,tG>aa
} LmROG-9
C91'dM
R6o07.]
public int getNSplitter() ]K5j(1EN
{ bM W}.v!
return nSplitter; *$t=Lh
} 7W/55ZTmJ
1OK~*=/4
a\MJh+K
public void setNSplitter(int nCount) Hs.5@l
{ d\ 7OtM
nSplitter = nCount; DQN"85AIZ
} .,p@ee$q
} 'A/{7*,
Co<F<eXe
#@M'*X_%}K
/* V8%( h[
**Utility.java Zqg AgN@
*/ bwjLMWEVq
package NetFox; t/x]vCP,2D
90Z4saSUw
y8di-d3_
public class Utility { ;ejtP #$
j{%'A
S }G3ha
public Utility() F B&l|#e
{ bFIv}c+;
j4D`Xq2X
Zr!CT5C5
} te3\MSv;O
y2x)<.cDP
//线程睡眠 _cc9+o
public static void sleep(int nSecond) wqQrby<
{ \z-OJ1[F
try{ 5[+E?4,&
Thread.sleep(nSecond); x@VZJrQQ
} hQJ- ~
catch(Exception e) 2\xEMec
{ tjDCfJx*
e.printStackTrace (); w}(Ht_6q{
} &K,rNH'R
} Wl>$<D4mO[
9>L{K
//日志 KSl@V>!_
public static void log(String sMsg) yuB\Z/
{ 8&y3oxA,
System.err.println(sMsg); ^ G>/;mZ
} =/^{Pn
FPuF1@K
u6p nO
public static void log(int sMsg) V34]5
{ 1d~cR
System.err.println(sMsg); }zwHUf9q1
} 6:Zd,N=
} l$!g#?w
oIY@xuj
ca!x{,Cvnj
/* x4S0C[k
**TestMethod.java l`<u\],
*/ 0o&c8?@j
package NetFox; - z"D_5
l*4_
CEb al\R
public class TestMethod { @I0[B<,:G
[yfi:|n1
qRA,-N
public TestMethod() xcu:'7'K[
{ ///xx/weblogic60b2_win.exe 0VlB7oF
try{ y{uN+QS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); x5nw/''[2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f5|Ew&1EP
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1ml{oqNj
fileFetch.start(); bp(X\:zAy
} 4>8'.8S
catch(Exception e){e.printStackTrace ();} tv7A&Z)Rh
75#&hi/~
j[YO1q*
} ' +[fJ>Le
J@pCF@'
3%SwCYd
public static void main(String[] args) T,Zfz9{n
{ g:>Mooxzi
new TestMethod(); U6R~aRJ;
} i_qR&X
} R4g% $}
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