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)); vw5f.8T;w
} Z:DEET!c'k
for(int i=0;i<nEndPos.length-1;i++) RO[Ko-m|/N
{ ph{p[QI:{X
nEndPos = nStartPos[i+1]; $&~/`MxE
} O4RNt,?l
nEndPos[nEndPos.length-1] = nFileLength; ~\kJir
} s7.2EkGl=
} kP~'C'5Ys
<k?ofE1o
b~fX=!M
//启动子线程 ]x1MB|a6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; W,"|([t4.\
for(int i=0;i<nStartPos.length;i++) 9zSHn.y
{ CT,caa
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DP\s-JpI[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'QGacV
nStartPos,nEndPos,i); B?Ac
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KwK[)Cvv
fileSplitterFetch.start(); x{{QS$6v
} !$Aijd s5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]T|9>o!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Xou1X$$z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [p[nK=&r
nEndPos = " + nFileLength); j(^ot001%v
// fileSplitterFetch[nPos.length-1].start(); maAZI-H{
{6{y"8
&7Frg`B&:
//等待子线程结束 AzAD76iNv
//int count = 0; \$:KfN>WY
//是否结束while循环 Fx,08
boolean breakWhile = false; ?~~sOf AP
!<r+h,C
hoY.2 B_
while(!bStop) ah<1&UG,
{ o&uO]
write_nPos(); I@Zd<Rn
Utility.sleep(500); !OWPwBm;
breakWhile = true; 'F%4[3a$\n
Z|;<:RKWY
_svEPHU
for(int i=0;i<nStartPos.length;i++) h'VN& T,
{ ?_mcg8A@@*
if(!fileSplitterFetch.bDownOver) (ii6w d<*
{ x,$N!X
breakWhile = false; J-*&&
break; Gt#Jr!N~
} #vrxhMo
} qu]ch&"?U
if(breakWhile) b`"E(S/
break; Ci%u =%(
iEx.BQ+
&:}e`u@5|
//count++; L9tjHC]
//if(count>4) L%](C
// siteStop(); ^0"^Xk*
} 1'ne[@i^/
sX&.8
0dS}pd">k
System.err.println("文件下载结束！"); .5Y%I;~v
} jVP70c
catch(Exception e){e.printStackTrace ();} *hVbjI$
} GC?X>AC:
|GuIp8~
RmS|X"zc
//获得文件长度 Z(Da?6#1
public long getFileSize() +pYrAqmO-
{ sYV7t*l
int nFileLength = -1; []HMUL]"
try{ 5.gM]si
URL url = new URL(siteInfoBean.getSSiteURL()); u] C/RDTH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TymE(,1
httpConnection.setRequestProperty("User-Agent","NetFox"); hUirvDvX
q6A!xQs<
9pPb]v,6
int responseCode=httpConnection.getResponseCode(); p- 5)J&
if(responseCode>=400) _;mN1Te
{ O%)@> 5#S
processErrorCode(responseCode); RjS;Ck@;
return -2; //-2 represent access is error )"?6EsSF
} fDc>E+,
[8*Ovd
cBf9-k
String sHeader; V:F;Nq%+j
w0QN5?
e&[gde(
for(int i=1;;i++) wX}N===
{ ;\`~M
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Enee\!@v
//Utility.log(in.readLine()); gfQ&U@N
sHeader=httpConnection.getHeaderFieldKey(i); "zW3dKVc
if(sHeader!=null) #PnuR2s7.
{ S,T?(lSl
if(sHeader.equals("Content-Length")) }.Eq_wP<
{ WqN=D5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \m-fLX
break; ~~:w^(s9
} a%*l]S0z"
} ~ILig}I
else ;9r Z{'i+|
break; Q(SVJ
} @rs(`4QEh
} R"(rL5j
catch(IOException e){e.printStackTrace ();} v-6"*EP
catch(Exception e){e.printStackTrace ();} YwGc[9=n
qGMM3a)Q
';`fMcN
Utility.log(nFileLength); Ke-Q>sm2Q
kN uDoo]z
z9:@~3k.
return nFileLength; $iQ>c6
} x_1JQDE
}*Qd]\fy
tq=1C=h
//保存下载信息（文件指针位置） dDH+`;$.
private void write_nPos() F\1nc"K/(
{ y7SOz'd
try{ :0o $qz2
output = new DataOutputStream(new FileOutputStream(tmpFile)); Z4FyuWc3
output.writeInt(nStartPos.length); b ABx'E
for(int i=0;i<nStartPos.length;i++) fs4pAB#F
{ "cjZ6^Hum
// output.writeLong(nPos); Mr'}IX5
output.writeLong(fileSplitterFetch.nStartPos); M,V+bt
output.writeLong(fileSplitterFetch.nEndPos); HE&,?vioy
} ~`2w ul
output.close(); N/)mw/?i
} pTq,"}J!+
catch(IOException e){e.printStackTrace ();} U -~%-gFC
catch(Exception e){e.printStackTrace ();} GypZ!)1
} 8xhXS1
4mOw[}@A
PpMZ-f@
//读取保存的下载信息（文件指针位置） '|^LNAx
private void read_nPos() dJ\6m!Mp
{ A9PXu\%y
try{ ,oe e'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PJj{5,#@3
int nCount = input.readInt(); =/=x"q+X
nStartPos = new long[nCount]; Ab7hW(/
nEndPos = new long[nCount]; /uI/8>p(
for(int i=0;i<nStartPos.length;i++) b~06-dk1
{ ulFU(%&
nStartPos = input.readLong(); o;Ijv\Em
nEndPos = input.readLong(); 4W8rb'B!Ay
} |Hn[XRsf
input.close(); IV^LYu
} Bc}<B:q%b
catch(IOException e){e.printStackTrace ();} `7jm
catch(Exception e){e.printStackTrace ();} Fk D
} mOwgk7s[J
>7!aZO
_dqjRhu
private void processErrorCode(int nErrorCode) _5a]pc$\Y]
{ rh2pVDS
System.err.println("Error Code : " + nErrorCode); IWu^a w
} i]GBu
!s,<hU#
c5P52_@
//停止文件下载 c?) pn9
public void siteStop() 6A M,1
{ A{h hnrr8
bStop = true; , >Y.!
for(int i=0;i<nStartPos.length;i++) _yjM_ALjo
fileSplitterFetch.splitterStop(); T\c;Ra
?>MD/l(l
DHpU?;|3
} m6V1m0M
} 5X&<+{bX
//负责部分文件的抓取 Bir}X
**FileSplitterFetch.java oSNB\G<
*/ 80$P35Q"
package NetFox; D{o1G?A
yP0P-8
iM2 EEC
import java.io.*; fEs957$
import java.net.*; `'Ta=kd3
wI>JOV7
L:YsAv
public class FileSplitterFetch extends Thread { 1hZM))
y:4Sw#M%(
;0E"4(S.q1
String sURL; //File URL j-gLX
long nStartPos; //File Snippet Start Position ;KQ'/nII
long nEndPos; //File Snippet End Position 2BH>TmS
int nThreadID; //Thread's ID a2/r$Tgm
boolean bDownOver = false; //Downing is over 9?D7"P+
boolean bStop = false; //Stop identical s cR-|GuZ
FileAccessI fileAccessI = null; //File Access interface &_4A6
UTA0B&aB
+lJuF/sS8m
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 37p0*%a":
{ #BS]wj2#
this.sURL = sURL; B0p>'O2
this.nStartPos = nStart; SUD]Wl7G`r
this.nEndPos = nEnd; =)M8>>l
nThreadID = id; -Kg@Sj/U}R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'lC"wP&$
} '5ky<
x|0Q\<mEe
Y@eHp-[
public void run() H[@}ri<
{ R'dF<&Kj|
while(nStartPos < nEndPos && !bStop) 3JW9G04.
{ fH`1dU
C*Ws6s>+z
BT>*xZLpS
try{ p<*-B
URL url = new URL(sURL); 0nx <f>n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C,2IET
httpConnection.setRequestProperty("User-Agent","NetFox"); h83ho
String sProperty = "bytes="+nStartPos+"-"; D\({]oj]
httpConnection.setRequestProperty("RANGE",sProperty); >[|:cz
Utility.log(sProperty); -D:J$d 6R<
W}L=JJo},
eE7Rd>
InputStream input = httpConnection.getInputStream(); jLr8?Hyf
//logResponseHead(httpConnection); 4L!{U@'
IUd>jHp`6
ItM?nyA
byte[] b = new byte[1024]; KH pxWq
int nRead; KXw \N!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) um,/^2A
{ N)poe2[
nStartPos += fileAccessI.write(b,0,nRead); /2'\ya4B
//if(nThreadID == 1) nr&G4t+%Hv
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z*yN*M6t
} u"T5m
);))kYr
zN5i}U=|r
Utility.log("Thread " + nThreadID + " is over!"); e}[$ =
bDownOver = true; 4] ?
//nPos = fileAccessI.write (b,0,nRead); oPa2GW8
} *qOo,e
catch(Exception e){e.printStackTrace ();} d1y(Jt
} 8.k"kXU@n
} IR/0gP
"Wi`S;
X0vkdNgW
//打印回应的头信息 |lJXI:GG
public void logResponseHead(HttpURLConnection con) /2l4'Q=
{ r}hj,Sq'
for(int i=1;;i++) -8 &f=J)
{ $6y1';A
String header=con.getHeaderFieldKey(i); GQ8I |E
if(header!=null) Z?nMt
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z[t$[Qg
Utility.log(header+" : "+con.getHeaderField(header)); ybS7uo
else AO']Kmm
break; 5yA^n6
} #{h4lte
} |{9"n<JW
Y!POUMA }A
1M3U)U
public void splitterStop() SF.,sCk
{ a S<JsB
bStop = true; 6 Dg[b
} h@W}xT
|d%Dw^
QyHUuG|g
} y|MW-|0=!
t4gD*j6J3
sp_(j!]jX
/* XLmbpEh
**FileAccess.java Opjt? ]
*//文件访问(定位，写) kdmVHiGF
package NetFox; sgCIY:8
import java.io.*; PI{sO |
+,|-4U@dl
PKjA@+
public class FileAccessI implements Serializable{ *f4KmiQ~%
M/1Q/;0P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4&y_+
RandomAccessFile oSavedFile; L\-T[w),z7
long nPos; q>Q|:g&:
siD Sm
QT|mN
public FileAccessI() throws IOException CS"p[-0
{ &UzZE17R
this("",0); {g @ *jo&
} @'}X&TN<a
pg>P]a{
-9aht}Z
public FileAccessI(String sName,long nPos) throws IOException 'm2,7]
{ 5T
oSavedFile = new RandomAccessFile(sName,"rw"); <c\aZ9+V
this.nPos = nPos; B]Zsn`n
oSavedFile.seek(nPos); LG,RF:
} e,4!/|H:
=r_ SMTu
Mb<KZ_wYOX
public synchronized int write(byte[] b,int nStart,int nLen) QPFpGS{d
{ g:2/!tujL
int n = -1; mB1)!
try{ rBny*!n
oSavedFile.write(b,nStart,nLen); BR0bf5T/
n = nLen; 9s7B1Pf
} Pu9.Uwx
catch(IOException e) XkK16aLE
{ &[Sw:{&*jv
e.printStackTrace (); KX9ZwsC0
} /4T%&#6s
?v")Z0 ~
94a_ W9
return n; \\/X+4|o'
} -_314j=`/
+QHhAA$
u{3KV6MS
} S((8DSt*
He]F~GXP
ntF(K/~Y
/* GB !3Z
**SiteInfoBean.java "^trHh8=
*/ ~z aV.3#
package NetFox; ~P/G^cV3s
L9kSeBt
tjTF?>^6|
public class SiteInfoBean { [2FXs52
)Tb;N
pD>3c9J'^F
private String sSiteURL; //Site's URL J`x9XWYw
private String sFilePath; //Saved File's Path kh5V&%>?
private String sFileName; //Saved File's Name d")r^7
private int nSplitter; //Count of Splited Downloading File 8WyG49eic
-#i%4[v
Z7f~|}
public SiteInfoBean() d@l;dos),
{//nSplitter的缺省值为5 CjST*(,b
//default value of nSplitter is 5 <y'ttxeS
this("","","",5); @+2Zt%
} V2y[IeSQ
P`oR-D
D=OU61AA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >N3{*W
{ MD On; Af>
sSiteURL= sURL; A9R}74e4g
sFilePath = sPath; 3n/L;T,X
sFileName = sName; w%ip"GT,
this.nSplitter = nSpiltter; r;'!qwr
s=d?}.E$
j=gbUXv/
} EP8LJzd"
J\{)qJ*jp
$_ NaxV
public String getSSiteURL() D{4 Y:O&J
{ e-s@@k
return sSiteURL; *PI3L/*
} ^Uf`w7"iY
h\dIp`H
h!Q>h7
public void setSSiteURL(String value) _AO0:&
{ "E8!{
sSiteURL = value; LNg1q1P3
} K)14v;@
<AIsNqr
F0!r9U((
public String getSFilePath() ]6aM %r=c
{ t #AQD]h
return sFilePath; Iq5F^rH`[
} U-k;kmaj
|'J3"am'
i3GvTg-X
public void setSFilePath(String value) ;'Y?wH[
{ -@73"w/
sFilePath = value; cn#a/Hx
} yO($KL+
Z5U~g?
PY2`RZ/@
public String getSFileName() 9w(j2i q
{ K1hw'AaQ
return sFileName; OYzJE@r^
} ZN)/doK
SB;Wa%
>}I}9y+
public void setSFileName(String value) }+B7C2_\
{ f&`*x t/
sFileName = value; \?g%>D:O;
} (r|T&'yK
7q?YdAUz
L=p.@VSZ
public int getNSplitter() +-Dd*yD6<
{ c`>\R<Z ]
return nSplitter; xvkof 'Q)
} yO6i "3
u7;A`
i~.[iZf|
public void setNSplitter(int nCount) F>M$|Sc2
{ zPmVECS
nSplitter = nCount; d!d 3r W;A
} ^Y&Cm.w
} ^d"J2n,7L
oaKf{$vg
V":BAn
/* S ~_%
**Utility.java I45A$nV#Q
*/ GBQb({
package NetFox; `%=Jsi0.Nq
i`Yf|^;@2>
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public class Utility { OBl8kH(b>
ZMe|fn
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public Utility() 7^; OjO@8
{ d#*5U9\z
Z^|C~lp;n
bXfOZFzq)
} "VeUOdNA>
d5%*^nMpY
//线程睡眠 1^;h:,e6
public static void sleep(int nSecond) rEf\|x=st:
{ "tark'
try{ 4Rm3'Ch
Thread.sleep(nSecond); U&5zs r
} |x4yPYBL
catch(Exception e) 9JtvHUkO
{ N|j.@K
e.printStackTrace (); RmQt%a7\{
} iF0a
} K8Y/XEK
5 QeGx3'
//日志 jysV%q 3
public static void log(String sMsg) Dmi;# WY
{ >SJ$41"E
System.err.println(sMsg); ]~zJ7I
} h=tu+pn
16y$;kf8
c-T ^ aR
public static void log(int sMsg) gh}AD1TN]
{ U{_s1
System.err.println(sMsg); 7`/qL "
} rrWk&;?
} L8zqLDi&
a7|&Tbv
;40m goN
/* <f6PULm
**TestMethod.java J){\h-4
*/ ZX;k*OrW
package NetFox; }^<zVdwp
FNM"!z
_PbfFY #
public class TestMethod { Mh|`XO.5I
-X[[ OR9+
\?^wu
public TestMethod() PQ]9xzOg[
{ ///xx/weblogic60b2_win.exe AL7O-D
try{ O-5U|wA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hyKg=Foq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #<PdZl R
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5Nb_K`Vp*
fileFetch.start(); X-,y[ )
} %`1vIr(7
catch(Exception e){e.printStackTrace ();} ewG21 q$
h /QP=Zd
ug,|'<G+
} D:E_h
?v8k& q^q
"V0:Lq
public static void main(String[] args) 7 !.8#A':
{ d-sh6q5
new TestMethod(); -C}59G8
} BmFME0
} O`jA-t
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