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)); @px2/x
} 1ml>
for(int i=0;i<nEndPos.length-1;i++) *;@V5[^3I?
{ W: R2e2
nEndPos = nStartPos[i+1]; k|Mj|pqA
} z/Z 0cM#
nEndPos[nEndPos.length-1] = nFileLength; #~QkS_
} t)o!OEnE
} g:<2yT
7.U CX"
MG6taOO!
//启动子线程 UP]X,H~stU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6+`+$s0
for(int i=0;i<nStartPos.length;i++) Zpc R
{ whFaL}2C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d h5%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /`$9H|
nStartPos,nEndPos,i); q$IgkL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jd#g"a>zZ
fileSplitterFetch.start(); "g}mxPe
} x[L/d"Wf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >F7v'-*{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vU|=" #
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |hGi8
nEndPos = " + nFileLength); kD1[6cJ!=.
// fileSplitterFetch[nPos.length-1].start(); +9Vp<(
QE8;Jk-
)2vkaR
//等待子线程结束 p+6L qk<
//int count = 0; P(h[QAM
//是否结束while循环 ^}Vx5[
boolean breakWhile = false; e+416 ~X v
X'[93 C|K
sX_6qKUH
while(!bStop) a(cZ]`s]*
{ h|m>JDxn
write_nPos(); w K)/m`{g
Utility.sleep(500); o m9zb&{tu
breakWhile = true; IbV 7}
oY Y?`<N#
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for(int i=0;i<nStartPos.length;i++) +7%}SV 2)
{ 4l)Q
if(!fileSplitterFetch.bDownOver) 1=NP=ZB
{ ;(0<5LQ
breakWhile = false; FQ6jM~
break; XQW9/AzNf
} _}G1/`09#
} /D@(o`a
if(breakWhile) N5m+r.<;
break; lxSCN6
#\DKU@|h
P[q`{TdV
//count++; "WPFZw:9
//if(count>4) WBOebv
// siteStop(); %N.qu_,IZ
} +2&+Gh.h
+,wCV2>\3
(zv)cw%
System.err.println("文件下载结束！"); (>.+tq}
} C{gY*+
catch(Exception e){e.printStackTrace ();} LS(J%\hMDm
} b Ag>;e(
j=>:{`*c
/U1&#"P
//获得文件长度 w]-,X`
public long getFileSize() Gh.@l\|tf
{ 7|vB\[s
int nFileLength = -1; ;`CNe$y
try{ T1Gy_ G/
URL url = new URL(siteInfoBean.getSSiteURL()); FEoH$.4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;giW
httpConnection.setRequestProperty("User-Agent","NetFox"); e/S^Rx4W
+#$(>6Zu"{
!/]vt?v#^
int responseCode=httpConnection.getResponseCode(); )cF1?2
if(responseCode>=400) 7"|j.Yq$H{
{ J|Af`HJ
processErrorCode(responseCode); =A yDVWpE
return -2; //-2 represent access is error vH`m W`=
} aM2[<m}
*Y!c6eA
9bE/7v
String sHeader; }iu(-{Z
'OERW|BO
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for(int i=1;;i++) 3B+ F'k&#
{ aC9PlKI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S zqY@
//Utility.log(in.readLine()); BkO)hze
sHeader=httpConnection.getHeaderFieldKey(i); C{"uz_Gh
if(sHeader!=null) ?:8wDV
{ "M`ehgCBr
if(sHeader.equals("Content-Length")) c<T'_93
{ VlLc[eVV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !"dn!X
break; gJn_Z7MgJ
} UN,y/V
} fxR}a,a
else $ 2/T]
break; ,vN0Jpf}\8
} \q |n0>
} @qGg=)T
catch(IOException e){e.printStackTrace ();} vWM'}(
catch(Exception e){e.printStackTrace ();} [+j39d.Q
#c2InwZV
s3., N|
Utility.log(nFileLength); L.]mC!
9F*],#ng
.JJ^w!|>#
return nFileLength; NbDfD3 1GK
} eqFOPK5q
a%h'utF{[
#_zd`s3k
//保存下载信息（文件指针位置） Qey6E9eCA
private void write_nPos() DJm/:td
{ 4Pm+0=E
try{ Aj22t
output = new DataOutputStream(new FileOutputStream(tmpFile)); WecJ^{g>r{
output.writeInt(nStartPos.length); *C0gpEf9S
for(int i=0;i<nStartPos.length;i++) CYxrKW l:'
{ SdI/
// output.writeLong(nPos); 7+h*&f3>
output.writeLong(fileSplitterFetch.nStartPos); wn$:L9"YN
output.writeLong(fileSplitterFetch.nEndPos); 4-YXXi}
} N%2UL&w#B
output.close(); Ya_4[vR<
} /_,} o7@t~
catch(IOException e){e.printStackTrace ();} _z3Hl?qk=
catch(Exception e){e.printStackTrace ();} 5xEk 7g.
} iN}BMd.U
TF@HwF"#
wq( m%F
//读取保存的下载信息（文件指针位置） /@*J\0h(-
private void read_nPos() O>![IH(L
{ 0M?nXHA[
try{ vGk}r
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); rLzYkZ
int nCount = input.readInt(); >QusXD"L>
nStartPos = new long[nCount]; )~](qLSl
nEndPos = new long[nCount]; ^1%gQ@P
for(int i=0;i<nStartPos.length;i++) M?UlC
{ OoFQ@zE7%
nStartPos = input.readLong(); c0H8FF3
nEndPos = input.readLong(); ~'4:{xH
} >:ZlYZ6sI
input.close(); GC3:ZpV`
} kt";Jx
catch(IOException e){e.printStackTrace ();} b=#3p
catch(Exception e){e.printStackTrace ();} ;5*)kX
} !6wbg
G0^O7w^5
MRB>(}
private void processErrorCode(int nErrorCode) 3xW;qNj:!l
{ ;'Pi(TA)
System.err.println("Error Code : " + nErrorCode); n ^T_pqV?X
} TwZvz[u
qdn\8Pn
q5$z:'zE
//停止文件下载 mX8A XWIa
public void siteStop() vWJhSpC[
{ 5T[9|zJs
bStop = true; ==psPyLF@
for(int i=0;i<nStartPos.length;i++) i*9[El
fileSplitterFetch.splitterStop(); `TkIyGr
x*#F|N4~',
1%L* 9>e
} ]`D(/l'
} ^}2 ie|
//负责部分文件的抓取 Qa,^;hZWS
**FileSplitterFetch.java !U"1ZsO)l
*/ t9&z|?Vz
package NetFox; E(T6s^8
xNNoB/DR
ta+'*@V+G
import java.io.*; M} IRagm
import java.net.*; 6'Sc=;;:
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}lgqRg)F9[
public class FileSplitterFetch extends Thread { X$O,L[] 4
6,'!z ?d%
@=c{GAj
String sURL; //File URL O_f|R1G5z
long nStartPos; //File Snippet Start Position /$hfd?L
long nEndPos; //File Snippet End Position `d=$9Pi
int nThreadID; //Thread's ID EX>|+zYL
boolean bDownOver = false; //Downing is over bOCdf"!g
boolean bStop = false; //Stop identical {Izg1N
FileAccessI fileAccessI = null; //File Access interface ?ng?>!
7"f$;CN?~
`07u}]d8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fB5Bh;K
{ ay2 m!s Q
this.sURL = sURL; Rg&6J#h
this.nStartPos = nStart; z[Kxy1,
this.nEndPos = nEnd; `hM:U
nThreadID = id; Ep}KIBBO
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O.=~/!(
} {6<7M
)o[ O%b
yI9l*'
public void run() xZ@H{):
{ b?oT|@
while(nStartPos < nEndPos && !bStop) q[]!V0Ek10
{ $JTy`g0>x
1h\:Lj
oKTIoTb
try{ _QtqQ~f
URL url = new URL(sURL); 9`^VuC'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?B %y)K
httpConnection.setRequestProperty("User-Agent","NetFox"); 3V`K^X3
String sProperty = "bytes="+nStartPos+"-"; vi0% jsI
httpConnection.setRequestProperty("RANGE",sProperty); u+s#Fee I
Utility.log(sProperty); L6j 5pI
$*%Ml+H-
uLb- NxQ-
InputStream input = httpConnection.getInputStream(); dUn8Xqj1
//logResponseHead(httpConnection); o})4Jt1vj
uw+v]y
8Es]WR5 ^
byte[] b = new byte[1024]; @hm%0L
int nRead; TE*$NxQ 2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0+8ThZ?n
{ %_1~z[Dv
nStartPos += fileAccessI.write(b,0,nRead); /-$`GT?l
//if(nThreadID == 1) Fm-W@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3h"; 2
} O6;>]/`
m7kDxs(KO
U:MkA(S%c
Utility.log("Thread " + nThreadID + " is over!"); <_ */
bDownOver = true; _\"P<+!
//nPos = fileAccessI.write (b,0,nRead); N{/q p
} X3]E8)645N
catch(Exception e){e.printStackTrace ();} |.:O$/ Tt[
} %>i7A?L
} mo#4jtCE
pP?J(0Q~
T]EXm/
//打印回应的头信息 Sct-,K%i
public void logResponseHead(HttpURLConnection con) Vw9^otJu
{ *@G4i
for(int i=1;;i++) 5G){7]P+r"
{ *^c4q|G.-
String header=con.getHeaderFieldKey(i); v!@/
if(header!=null) ItKwB+my
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1elcP`N1
Utility.log(header+" : "+con.getHeaderField(header)); {L$b$u$7:
else W\U zw,vI
break; Oe$cM=Yf
} p>K'6lCa
} :M|c,SQK
U3kf$nbV/J
FEaf&'G]
public void splitterStop() [X^JV/R
{ v.6"<nT2
bStop = true; =]xNpX)
} .1I];Cy0D
r'&9'rir2
9aZ3W<N`M
} r=L9x/r
qR]4m]o
B[4y(Im
/* $'9r=#EH
**FileAccess.java DGHX:Ft#
*//文件访问(定位，写) 83i%3[L
package NetFox; (^a;2j9
import java.io.*; L{^DZg|E
pJa FPO..|
ZFW}Vnl
public class FileAccessI implements Serializable{ `yYgL@Zt
Oku4EJFJ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m3_e]v3{o
RandomAccessFile oSavedFile; P603P
long nPos; FbFUZ^Zj
=#Vdz=.
fwsq:
public FileAccessI() throws IOException ;S?1E:\av
{ K/\#FJno
this("",0); ;xB"D0~,1
} D<++6HN&#
Mh+'f 93
>j`*-(`2fa
public FileAccessI(String sName,long nPos) throws IOException i;)g0}x`
{ 0BaL!^>
oSavedFile = new RandomAccessFile(sName,"rw"); j{U-=[$'
this.nPos = nPos; /=e[(5X|O
oSavedFile.seek(nPos); sWavxh8A
} ziH2<@
j~Gu;%tq
bq(*r:`"
public synchronized int write(byte[] b,int nStart,int nLen) [PX'Jer
{ BLaXp0
int n = -1; z%Z}vWn
try{ &g& &-=7)
oSavedFile.write(b,nStart,nLen); =l7LEkR
n = nLen; )&R;!#;5
} ['R=@.
catch(IOException e) hLm9"N'Pf
{ B.P64"w
e.printStackTrace (); "BFW&<1
} [tD*\\IA
iBo-ANnK9
Uw&+zJ
return n; <q[*kr
} 'E&K%/d
~:t2@z4p
p\-.DRwT`
} C>K/C!5?
s}z,{Y$-t
X!2|_
/* }SN'*w@E
**SiteInfoBean.java oTa! F;I
*/ gA[M
package NetFox; 4l$8lYi
ycE<7W
@nT8[v
public class SiteInfoBean { (QRl -| +
l&|{uk
!k s<VJh
private String sSiteURL; //Site's URL vy#c(:UQR
private String sFilePath; //Saved File's Path $`=?Nb@@#
private String sFileName; //Saved File's Name YKx0Zs
private int nSplitter; //Count of Splited Downloading File [ThzLk#m
bs`/k&'
wcL0#[)
public SiteInfoBean() ~o2{Wn["
{//nSplitter的缺省值为5 Aj`4uFhiL
//default value of nSplitter is 5 ffB]4
this("","","",5); xK y<o
} A&M/W'$s
>u/yp[Ky
(w^&NU'e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `q@~78`
{ \)#3S $L~
sSiteURL= sURL; &qpA<F@7
sFilePath = sPath; 3+$O#>
sFileName = sName; 8/F2V?iT
this.nSplitter = nSpiltter; R|M:6]}
s24H.>Z
C {,d4KG
} (i?^g &
*FE<'+%
[ho'Pc3A<
public String getSSiteURL() XM 7zA^-
{ WcJ{}V9
return sSiteURL; tV,zz;* Oe
} y@Or2bO#
'q-h kN
.F6#s
public void setSSiteURL(String value) <qy+@t
{ .iS]aJJ
sSiteURL = value; xD#/@E1'Y
} .iYgRW=T
@t^2/H ?O
<|_Ey)1 6
public String getSFilePath() JQ1VCG
{ ?yU#'`q
return sFilePath; a;zcAeX
} {Eb6.
oaK~:'
B)|s.Ez
public void setSFilePath(String value) -s1VlS/
{ d{m0uX56
sFilePath = value; Fi`:G}
} h P1|l
xV6j6k
hf-S6PEsM
public String getSFileName() ,]Ma,2
{ P}I*SV0
return sFileName; [KKoEZ
} `Qhh{
k$2Y)
6GN'rVr!Z
public void setSFileName(String value) ;uDFd04w [
{ +W1rm$Q
sFileName = value; k8JPu"R
} 9x1Dyz 2?F
PA/6l"-`3
b1OB'P8
public int getNSplitter() DNy)\+[
{ # 9t/j`{
return nSplitter; @e7+d@O<
} 3IkG*enI
!:8!\gE^P
6\K)\
public void setNSplitter(int nCount) *+z({S_Nv
{ ;1 fML,8
nSplitter = nCount; Pla EI p
} 88K*d8m
} S!]}}fKEFm
3:(`#YY
rij[ZrJ
/* 4Uiqi{}
**Utility.java z|2liQrf+
*/ KOQTvJ_#
package NetFox; Bz{ g4!ku
/b|sv$BN
xpk|?/6
public class Utility { {;zPW!G
4l*&3Ar
v+G:,Tc"
public Utility() ;D1IhDC
{ +\%zy=
xlLS`
rBf?kDt6l
} Ydx5kUJV<
;k8}D*?8
//线程睡眠 hA8 zXk/'8
public static void sleep(int nSecond) Z:_y,( 1Q
{ ?zEF?LJoK
try{ (AYD@
Thread.sleep(nSecond); 4=Ey\Px
} 1|VJND
catch(Exception e) NP8TF*5V
{ /HRaX!|E#
e.printStackTrace (); x_K%
} ~#CCRUhM
} J (h>
1GdD
//日志 Q Y'-]
public static void log(String sMsg) @2gMtf?<
{ K5SO($
System.err.println(sMsg); YSgF'qq\
} )VT/kIq-U
{/<&
(=j!P*
public static void log(int sMsg) w^gh&E
{ d%3BJ+J
System.err.println(sMsg); U\ued=H
} F 4/Uu"J:
} R=PzR;8
^ne8~ ;Q
7,TWCVap
/* ~|rkt`8p
**TestMethod.java 5WT\0]RUa
*/ ' T]oV~H
package NetFox; `?x$J 6p
dK: "
e`r;`a&
public class TestMethod { {P&^Erx
o2
8:xo ~Vc
public TestMethod() pC-OZ0
{ ///xx/weblogic60b2_win.exe =f!M=D
try{ ]aNnY?qW5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <Z'hZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); i1\2lh$
SiteFileFetch fileFetch = new SiteFileFetch(bean); BvF_9
fileFetch.start(); #=(op?]
} Ef.4.iDJrR
catch(Exception e){e.printStackTrace ();} SK52.xXJ
4Z}{hc\J
ItADO'M
} -(1\`g07
T;@>O^
9#ft;c
public static void main(String[] args) I?>T"nV +'
{ )\vHIXnfJ1
new TestMethod(); {R;M`EU>
} yU,xcq~l
} p'~5[JR:
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