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)); LFV;Y.-(h
} w#XE!8`
for(int i=0;i<nEndPos.length-1;i++) H\^5>ccU>V
{ C=%go1! $
nEndPos = nStartPos[i+1]; K& 2p<\2
} tlqDY1
nEndPos[nEndPos.length-1] = nFileLength; od?Q&'A
} q:1 1XPP
} 6t/})Xv
U{eC^yjt"o
bKG:_mWe w
//启动子线程 fgTvwOSk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |w /txn8G|
for(int i=0;i<nStartPos.length;i++) _.Uz!2
{ n1buE1r?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %>5Ht e<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =eTI@pN`
nStartPos,nEndPos,i); q`9~F4\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -+Quw2465^
fileSplitterFetch.start(); `C_#EU-
} dpE\eXoa,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {&w%3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }wj*^>*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "Z}0A/y
nEndPos = " + nFileLength); #;}IHAR
// fileSplitterFetch[nPos.length-1].start(); .'D+De&y
POUB{ba
;#fB=[vl";
//等待子线程结束 gEU)UIJ
//int count = 0; 5g/^wKhKG
//是否结束while循环 K2:r7f
boolean breakWhile = false; dA\>z[n=
}[ux4cd8Y
ot(|t4^
while(!bStop) as~.XWa
{ rw_&t>Ri;
write_nPos(); $`_(%tl
Utility.sleep(500); PX2Ejrwj
breakWhile = true; 7b@EvW6X}
!i}G>*XH,
R%3H"FU9w
for(int i=0;i<nStartPos.length;i++) Y k~ i.p
{ _2f}WY3S
if(!fileSplitterFetch.bDownOver) 8a. |CgI#h
{ T7cT4PAW
breakWhile = false; \mWXr*;
break; S)JZb_
} e/@udau
} Yn1U@!
if(breakWhile) !jYV,:'
break; hTVN`9h7
>SfC '*1
j] M)i:n
//count++; ~R!(%j ]
//if(count>4) s/P\w"/fN
// siteStop(); rYm<U!k
} !4.;Ftgjn
)m5<gp`
y<3v/,Y
System.err.println("文件下载结束！"); G/<{:R"
} /:awPYGH<1
catch(Exception e){e.printStackTrace ();} f()^^+
} '*-X3p
b;!ilBc
S$muV9z2=
//获得文件长度 :*c@6;2@
public long getFileSize() o#0NIn"GS/
{ 5\QNGRu"
int nFileLength = -1; -@^SiI:C
try{ &[RC4^;\V
URL url = new URL(siteInfoBean.getSSiteURL()); fjp>FVv3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {"{J*QH
httpConnection.setRequestProperty("User-Agent","NetFox"); ;;l(
.=^h@C*
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int responseCode=httpConnection.getResponseCode(); B(^fM!_%-6
if(responseCode>=400) ;]nU->
{ @&EE/j^
processErrorCode(responseCode); ]p0m6}B
return -2; //-2 represent access is error 2px5>4<
} BLMcvK\9
j#!J hi
~xvQ?c?-
String sHeader; fCEd :Kr
_}JygOew
?{{E/J:%
for(int i=1;;i++) b[RBp0]x
{ ch :428
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %@pTEhpF
//Utility.log(in.readLine()); eTrGFe!8w
sHeader=httpConnection.getHeaderFieldKey(i); }[i35f[w
if(sHeader!=null) y)(SS8JR
{ \V: _Zs
if(sHeader.equals("Content-Length")) A9lqVMp64
{ 4eIu@ ";!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /I6?t=?<
break; hk,Q=};
} Oa@X! \
} dWm[#,Q?
else zROyG
break; D-,sF8{ i
} Pu axS
} T<!`~#kM
catch(IOException e){e.printStackTrace ();} )(DV~1r=
catch(Exception e){e.printStackTrace ();} dHOz;4_
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e,1Jxz4QH
Utility.log(nFileLength); [$H8?J
SB \ptF
]]`+aF0
return nFileLength; D 3Int0n
} 1/1P;8F@G
iZ_R oJ
7ic]q,
//保存下载信息（文件指针位置） 4&t6
private void write_nPos() mX|AptND
{ ]7xAL7x
try{ \=5CNe
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2d1'!B zDA
output.writeInt(nStartPos.length); Gl1`Nx0
for(int i=0;i<nStartPos.length;i++) J`"1DlH
{ fDbs3"H Q
// output.writeLong(nPos); m+uh6IqN./
output.writeLong(fileSplitterFetch.nStartPos); F ^E(AE
output.writeLong(fileSplitterFetch.nEndPos); E,C<ox4e
} fylaH(LER
output.close(); cwpDad[Kx
} 5~.\rcr%
catch(IOException e){e.printStackTrace ();} D=dY4WwG
catch(Exception e){e.printStackTrace ();} $X\BO&
} 6xBP72L;%"
&ul9N)A
(Yw5X_|
//读取保存的下载信息（文件指针位置） xX"?3%y>
private void read_nPos() 1p8E!c{}j
{ }#yRaIp
try{ ;W+.]_$6)T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N8nyTPw
int nCount = input.readInt(); #Q$4EQB
nStartPos = new long[nCount]; DI$zyj~3
nEndPos = new long[nCount]; X.272q<.
for(int i=0;i<nStartPos.length;i++) qt;6CzL C
{ 4AF"+L
nStartPos = input.readLong(); f-{[ushj
nEndPos = input.readLong(); ,;D74h2F
} Rj E,Wn
input.close(); >StvP=our
} Js=|r;'
catch(IOException e){e.printStackTrace ();} SH`"o
catch(Exception e){e.printStackTrace ();} ".w*_1G7U
} *`l>1)B>
&Vonu*
3'.OghI
private void processErrorCode(int nErrorCode) hw1ZTD:Y
{ txL5'mK
System.err.println("Error Code : " + nErrorCode); (U7%Z<
} H%%#^rb^
@*2FG\c<
=6+BBD
//停止文件下载 G:@gO2(D
public void siteStop() gE$dz#t.
{ g#70Sg*d
bStop = true; 47icy-@kg
for(int i=0;i<nStartPos.length;i++) 0kiW629o
fileSplitterFetch.splitterStop(); Rw. Uz&
L)w& f
2"i<--Y
} a7d782~
} }RoM N$r
//负责部分文件的抓取 -D(UbkPw
**FileSplitterFetch.java !w/~dy
*/ 2{#quXN9
package NetFox; 6DR8(j)=[%
!'[sV^ds
wCI.jGSBW
import java.io.*; i_=P!%,
import java.net.*; FS@SC`~(
*y0`P0V|8
8a05`ZdP
public class FileSplitterFetch extends Thread { \<PX'mnO
@D60
'wQ=b
String sURL; //File URL sJ0y3)PQ
long nStartPos; //File Snippet Start Position # =322bnO
long nEndPos; //File Snippet End Position ^qk$W?pX
int nThreadID; //Thread's ID \T[*|"RFZ
boolean bDownOver = false; //Downing is over chiQ+
boolean bStop = false; //Stop identical Ar):D#D
FileAccessI fileAccessI = null; //File Access interface }& 1_gn15
J#X7Ss
3~ZtAgih%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :X$&gsT/,
{ Az)P&*2:'`
this.sURL = sURL; ;N/c5+
this.nStartPos = nStart; wvc?2~`
this.nEndPos = nEnd; r^\^*FD |
nThreadID = id; Q5jP`<zWU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z]Qm64^I
} Y@r#:BH)
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kv'n W
public void run() ?`w ~1
{ rzO:9# d
while(nStartPos < nEndPos && !bStop) Gpgi@ Uf
{ .z{7 rH
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h]D=v B
try{ :s$9#}hw,
URL url = new URL(sURL); KlrKGmy,)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N.&K"J
httpConnection.setRequestProperty("User-Agent","NetFox"); w1GCjD*y
String sProperty = "bytes="+nStartPos+"-"; qrdA?VV
httpConnection.setRequestProperty("RANGE",sProperty); o?%x!m>
Utility.log(sProperty); xpS#l"dr
\XpPb{:>
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InputStream input = httpConnection.getInputStream(); @RnGK 5
//logResponseHead(httpConnection); 3s|tS2^4
-({\eL$n
L~yy;)]W
byte[] b = new byte[1024]; gZPJZN/cpz
int nRead; f?{Y<M~]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ", |wG7N K
{ V)0bLR
nStartPos += fileAccessI.write(b,0,nRead); DL~LSh
//if(nThreadID == 1) 4$|G$h
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @*_K#3
} g`Rs;
Xpa;F$VI
,O-lDzcw
Utility.log("Thread " + nThreadID + " is over!"); 2`Pk@,:_
bDownOver = true; Lc.7:r
//nPos = fileAccessI.write (b,0,nRead); ~ h:^Q
} ^<E,aCy
catch(Exception e){e.printStackTrace ();} "~+K`*0r8
} ~\oJrRYR`
} SS`\,%aog
yV]-![`D
2.NzB7c*CM
//打印回应的头信息 v\HGL56T
public void logResponseHead(HttpURLConnection con) a1}W2;W0]g
{ Z>D7C?v:(
for(int i=1;;i++) bh_ALu^CSX
{ .Ftml'!
String header=con.getHeaderFieldKey(i); A] F K\
if(header!=null) SOUA,4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =-:o?&64
Utility.log(header+" : "+con.getHeaderField(header)); E@@quK
else R4v=i)A~Z
break; C2b.([HE
} '@W72ML.
} U}5uy9A
JZc5U}i
M.128J+xfS
public void splitterStop() -S|L+">=Z
{ ,{oANqP
bStop = true; `#(4K4]1.
} o?X\,}-s
grS,PKH
tl4;2m3w
} SMhT>dB
nBD7
%v|,-B7Yx
/* F(w>lWs;
**FileAccess.java 4s"HO/
*//文件访问(定位，写) O-G@To3\
package NetFox; &/zsIx+
import java.io.*; 77 `/YE#M
k\%{1oRA
NKMB,b
public class FileAccessI implements Serializable{ wHY;Y-(ZT
pG4Hy$e
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ! [:K/
RandomAccessFile oSavedFile; /!9949XV
long nPos; t=pG6U
#uH1!UQb
HD`%Ma Yhc
public FileAccessI() throws IOException I#mT#xs6
{ yy>4`_
this("",0); Uvuvr_IP
} S\f^y8*<
6[CX[=P30
D,)~j6OG8
public FileAccessI(String sName,long nPos) throws IOException BHU[Rz7x
{ wY=ky629
oSavedFile = new RandomAccessFile(sName,"rw"); s+CWyW@
this.nPos = nPos; O+e8}Tmm
oSavedFile.seek(nPos); \ 0CGS
} `\qU.m0(j
ypsCyDQK`
2T|L##C
public synchronized int write(byte[] b,int nStart,int nLen) 8^~ljf]6
{ l >O]Cpt
int n = -1; "w A8J%:
try{ IGp-`%9
oSavedFile.write(b,nStart,nLen); :2?'mKa7
n = nLen; %TR->F
} 8"4`W~ 3
catch(IOException e) >!oN+8[~
{ > W0hrt?b
e.printStackTrace (); ;j(xrPNb
} cis~]x%
0 @,@
d- ]%
return n; YnNei 7R
} xqG` _S l
.N5"IY6>
-Rf|p(SJ,E
} adxJA}K}
bEy%S"\<
<n#JOjHV
/* JD'/m hN0
**SiteInfoBean.java !k[zUti
*/ M35}5+
package NetFox; >DV0!'jW
[Y:HVr,
--]\z*x
public class SiteInfoBean { ~#-`Qh
"zv+|_ZAfd
$]hf2Yr(
private String sSiteURL; //Site's URL ))MP]j9 T
private String sFilePath; //Saved File's Path {jv1hKTa
private String sFileName; //Saved File's Name !"1bV [^
private int nSplitter; //Count of Splited Downloading File rKjQEO$yi
WUxr@0
jLEU V
public SiteInfoBean() jRBx7|ON
{//nSplitter的缺省值为5 (*2"dd
//default value of nSplitter is 5 x~(Ul\EX
this("","","",5); 8m9G^s`[
} FTB"C[>
lF#Kg!-l
0m@S+$v
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !X,S2-}"
{ ,CvU#ab8$
sSiteURL= sURL; 'DIE#l`
sFilePath = sPath; Q647a}
sFileName = sName; }x8fXdd
this.nSplitter = nSpiltter; PzF)Vg
[Z[)hUXE?
>,9t<p=Q
} >U}~Hv]
`C=p7%
m+!%+S1
public String getSSiteURL() J^?O]|
{ >:K3y$]_
return sSiteURL; c1z5t]d
} k'\RS6M`L
kC#;j=K?
v<-D>iJ
public void setSSiteURL(String value) |UBJu `%
{ ROfmAc
sSiteURL = value; )dvOg'it
} x~mXtqg
%?cPqRHJ ~
kiECJ@5p
public String getSFilePath() NR3IeTd
{ )-sEm`(`I9
return sFilePath; eygyVhJ
} ES+&e/G"ds
@.gCeMlOf
.)o5o7H
public void setSFilePath(String value) 'IgtBd|K>
{ a@X'oV`(2b
sFilePath = value; Kzmgy14o
} |n~v_V2.0
TX 87\W.
Wqqo8Y~fq
public String getSFileName() '|+_~ZO*d
{ =GpLlJ`-
return sFileName; mHhm~u
} ]A\n>Z!;
K;Xn!:) V:
E6G^?k~q
public void setSFileName(String value) {7;TQ?/
{ :DZiDJ@
sFileName = value; 6?Wsg`9
} 68d@By
kj[[78
U]P;X~$!
public int getNSplitter() ZzE&?
{ oNdO@i%.q4
return nSplitter; H4pjtVBr
} 9#agI|d~
~7k b4[
1|%$ie
public void setNSplitter(int nCount) 7,jqA"9
{ b_LzG_n!
nSplitter = nCount; d`xqs,0f
} N Lo>"<Xb
} Z,2uN!6
(thzWr6;
`?>OY&(
/* U_J|{*4S.!
**Utility.java OO@$jXZB
*/ _6|b0*jv'&
package NetFox; Zw3|HV(so
;xRyONt
9DT}sCLz:B
public class Utility { d EXw=u
'3xSzsDn
x^ Wgo`v)
public Utility() ,p2 Di
{ duM>(y
,5/gNg
\gzNMI*
} g_q{3PW.
HS2)vd@)
//线程睡眠 EEaFi8
public static void sleep(int nSecond) |GsLcUv6
{ Qejzp/2
try{ yZ2,AR%
Thread.sleep(nSecond); MdPwuXI
} !nd*U}q
catch(Exception e) 2vur_`cV
{ oi!E v_h
e.printStackTrace (); 1]qhQd-u
} C{,nDa?|
} d9^h YS{
`Ffn:=Do
//日志 \t(/I=E8/
public static void log(String sMsg) xE}q(.]
{ rVO+ vhih
System.err.println(sMsg); ClEtw
} ](O!6_'d
D4S>Pkv
%++q+pa
public static void log(int sMsg) ;TR.UUT
{ a7CJ~8-1K
System.err.println(sMsg); ^o{O5&i]
} w,P2_xk`
} :8rqTBa`
/!LfEO
lKa}Bcd
/* v<c8qg
**TestMethod.java Z$@Juv&>5^
*/ @hCGV'4
package NetFox; M^bujGD
+XQS -=
<?I~ +
public class TestMethod { 1M+mH#?
^,rbA>/L
m!PN1$9V
public TestMethod() |+[bKqI5
{ ///xx/weblogic60b2_win.exe 5bAy@n
try{ !W6]+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [#.QDe
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ul:jn]S*
SiteFileFetch fileFetch = new SiteFileFetch(bean); jKtbGVZ7r
fileFetch.start(); VfQSfNsi
} /2YI!U@A
catch(Exception e){e.printStackTrace ();} -dza_{&+iZ
b,!h[
T+gqu &9R
} *%MY. #
{? 6]_J
K}*s^*X
public static void main(String[] args) FkRrW^?5G
{ g{i(4DHm(
new TestMethod(); [WB8X,
} \Q &Kd|
} 2AdV=n6Z
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