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)); /nNN,hz
} J=I:CD%
for(int i=0;i<nEndPos.length-1;i++) Y"aJur=`
{ Vn}0}Jz
nEndPos = nStartPos[i+1]; ?P`K7
} -;m0R
nEndPos[nEndPos.length-1] = nFileLength; q,|j]+9q
} l<LI7Z]A
} AJ`h9%B
;:g@zAV
'Aq{UGN
//启动子线程 06Sceq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v%z=ysA
for(int i=0;i<nStartPos.length;i++) NP3y+s
{ J @1!Oq>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [D4SW#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *C*U5~Zq7:
nStartPos,nEndPos,i); E KLyma&}Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]MitOkX
fileSplitterFetch.start(); kfY}S
} 3$>1FoSk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )_S(UVI5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Hk.TM2{w
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;))+>%SGCt
nEndPos = " + nFileLength); l4YJ c
// fileSplitterFetch[nPos.length-1].start(); {@{']Y
|FZ/[9*
@9RM9zK.q
//等待子线程结束 {qJ1ko)$
//int count = 0; L+i=VGm0
//是否结束while循环 BG]#o|KW
boolean breakWhile = false; 9-a0:bP
Zt{[*~
#'szP\
while(!bStop) ~-Qw.EdC
{ &Q#66ev
write_nPos(); CXMLt
Utility.sleep(500); h]}wp;Z
breakWhile = true; #gs`#6 ,'
29] G^f>
e2oa($9
for(int i=0;i<nStartPos.length;i++) oY3;.;'bk
{ O;jrCB
if(!fileSplitterFetch.bDownOver) aSQ#k;T[
{ /%1ON9o>
breakWhile = false; 2-v%`fA
break; `kXs;T6&
} SRDp*
} p%=u#QNi
if(breakWhile) )}Kf=
break; Js?]$V"
vr6w^&[c^
A]oV"`f
//count++; p]+Pkxz]'
//if(count>4) hD!7Cl Q
// siteStop(); uZKr
} '-XXo=>0MV
s*]}QmRpr
;$wVu|&
System.err.println("文件下载结束！"); Z=o2H Bm7
} d^ 8ZeC#
catch(Exception e){e.printStackTrace ();} Om2d.7S
} ?NsW|w_
WP'!*[z
;h
//获得文件长度 ;dgp+
public long getFileSize() 7[XRd9a5(
{ -C]5>& W
int nFileLength = -1; >KhOz[Zg
try{ :':s@gqr
URL url = new URL(siteInfoBean.getSSiteURL()); 9qzHS~l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WW~sNC\3`(
httpConnection.setRequestProperty("User-Agent","NetFox"); p}~JgEE
;[OH(!
i<Zc"v;
int responseCode=httpConnection.getResponseCode(); VjZ|$k
if(responseCode>=400) 4!no~ $b
{ Q/0Tj]D
processErrorCode(responseCode); 7;wd(8
return -2; //-2 represent access is error `|&O*`
} @lrztM
A$0fKko
Pu$Tk|
String sHeader; ;iL#7NG-R
FWgpnI\X|{
+a{1)nCXe
for(int i=1;;i++) #.)0xfGW)n
{ TKmf+ZT*r
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -k e's
//Utility.log(in.readLine()); JP[K;/
sHeader=httpConnection.getHeaderFieldKey(i); y}ev ,j
if(sHeader!=null) >U27];}y
{ T+H!_ky`A
if(sHeader.equals("Content-Length")) .4!=p*Y
{ `Eo.v#<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i$6ypuc
break; Btn]}8K
} ; )@~
} _F|Ek;y%
else (gWm,fI RZ
break; 1^JS Dd
} 56kI 5:
} [5Mr@f4I
catch(IOException e){e.printStackTrace ();} ;"-&1qHN
catch(Exception e){e.printStackTrace ();} ,(^*+G.i
sWnLEw
jasy<IqT!{
Utility.log(nFileLength); K`fuf=
=$JET<(
s R/F"
return nFileLength; ')<hON44EX
} '!~)?C<
7n<::k\lb
F0Yd@Lk$_
//保存下载信息（文件指针位置） *#+An<iT ;
private void write_nPos() z[qDkL
{ "'?>fe\qG
try{ ^9:Z7 >Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); 59;KQ
output.writeInt(nStartPos.length); pB0 \\wR
for(int i=0;i<nStartPos.length;i++) ^WWQI+pk
{ }y gD3:vN7
// output.writeLong(nPos); vy:Z/1q
output.writeLong(fileSplitterFetch.nStartPos); PtiOz :zV
output.writeLong(fileSplitterFetch.nEndPos); >7DhTM-A
} 5vnrA'BhBU
output.close(); 4zFW-yy
} @*KZ}i@._
catch(IOException e){e.printStackTrace ();} 5#E`=C%
catch(Exception e){e.printStackTrace ();} &`2)V;t
} 8$Y9ORs4
A#YrWW
hf&9uHN%7m
//读取保存的下载信息（文件指针位置） f x+/C8GK
private void read_nPos() 88wa7i*
{ SSMHoJGm
try{ J)p l|I
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @_}P-h
int nCount = input.readInt(); r$s Qf&=
nStartPos = new long[nCount]; LyFN.2qw
nEndPos = new long[nCount]; %:* YO;dw'
for(int i=0;i<nStartPos.length;i++) :&."ttf=
{ tf`^v6m%]
nStartPos = input.readLong(); ds[|
nEndPos = input.readLong(); qF;|bF
} Se =`N
input.close(); t'k$&l}+
} 3AN/ H
catch(IOException e){e.printStackTrace ();} I^$fMdT
catch(Exception e){e.printStackTrace ();} $*=<Yw4
} bY~pc\V:`w
'E""amIJ
oe-\ozJ0
private void processErrorCode(int nErrorCode) 0oIe>r
{ 4 "'~NvO
System.err.println("Error Code : " + nErrorCode); &6nWzF
} ~oY^;/ j
svH !1b
?^\|-Gr
//停止文件下载 Z"fJ`--
public void siteStop() .U]-j\
{ 49HZ2`Y
bStop = true; pIqeXY
for(int i=0;i<nStartPos.length;i++) -PR N:'T
fileSplitterFetch.splitterStop(); v mk2{f,g
r3UUlR/Do
w ;^ra<*<+
} 86F1.ve
} >tW#/\x{
//负责部分文件的抓取 sLxc(d'A
**FileSplitterFetch.java #?:lb1
*/ gc$l^`+M
package NetFox; O3kA;[f;
hM@>q&q_
X45%e!
import java.io.*; -6B4sZpzD
import java.net.*; rmg}N
+TDw+
6qnzBA7
public class FileSplitterFetch extends Thread { c9h6C
Wvf ^N(
C1QA)E['V
String sURL; //File URL E hMNap}5"
long nStartPos; //File Snippet Start Position z-)O9PV
long nEndPos; //File Snippet End Position Lw>N rY(Y
int nThreadID; //Thread's ID BnasI;yWb
boolean bDownOver = false; //Downing is over wz%NbLy-
boolean bStop = false; //Stop identical *gWwALGo5
FileAccessI fileAccessI = null; //File Access interface $-sHWYZ
p0vVkdd
:"/d|i`T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G" "ZI$`
{ f%}xO+.s
this.sURL = sURL; -nV9:opD
this.nStartPos = nStart; P/_['7
this.nEndPos = nEnd; j&qub_j"xX
nThreadID = id; }*]-jWt1J\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gRcQt:
} (SAs-
[d]9Oa4
3h`f6
public void run() ]~siaiN[
{ 9XB8VKu8
while(nStartPos < nEndPos && !bStop) {I't]Qj_e
{ nAdf=D'P
|&i<bqLw:
{"KMs[M
try{ `<d }V2rdz
URL url = new URL(sURL); R (n2A$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &Au@S$ij
httpConnection.setRequestProperty("User-Agent","NetFox"); }k.Z~1y
String sProperty = "bytes="+nStartPos+"-"; ncT&Gr
httpConnection.setRequestProperty("RANGE",sProperty); h<<v^+m
Utility.log(sProperty); IW] rb/H
aK^q_ghh[
T]~xj4
InputStream input = httpConnection.getInputStream(); pTLCWbF?
//logResponseHead(httpConnection); 6.yu-xm
x7 ,5
tc_3sC7jN
byte[] b = new byte[1024]; - 1gVeT&
int nRead; .(k|wX[Fu~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %d9uTm;
{ eTcd"Kd/
nStartPos += fileAccessI.write(b,0,nRead); S3Jo>jXS "
//if(nThreadID == 1) @`9]F7h5W
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wN~_v-~*Q
} .HABNPNg(
V(!V_Ug9.
uW %#
Utility.log("Thread " + nThreadID + " is over!"); A|{(/G2*
bDownOver = true; (CWtLi"z
//nPos = fileAccessI.write (b,0,nRead); \:LW(&[!
} $6R-5oQ
catch(Exception e){e.printStackTrace ();} FGBbO\</
} H3-hcx54T
} e~"U @8xk~
;#< 0<
:?1Dko^
//打印回应的头信息 8'y$M] e9n
public void logResponseHead(HttpURLConnection con) 0?|<I{z2
{ *.w9c
for(int i=1;;i++) Z6MO^_m2
{ !0<,@v"
String header=con.getHeaderFieldKey(i); 44j*KsBf
if(header!=null) SiN0OB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]u/sphPe
Utility.log(header+" : "+con.getHeaderField(header)); b^vQpiz
else )Hr`MB
break; YKK*ER0
} XfIJ4ZM5
} Ar#(psU
B/Ws_Kv
deh*Ib:(S
public void splitterStop() )J(6xy
{ S~G]~gt
bStop = true; +D*Z_Yh6
} >9Vn.S
o}p n0KO,
,zY{
} xxQ;xI0+]
-jmY)(\
zX i'kB
/* A?OQE9'
**FileAccess.java &_8947
*//文件访问(定位，写) T6$+hUM$1
package NetFox; <(#ej4ar,
import java.io.*; ~v6D#@%A
|CbikE}kL
X1_5KH
public class FileAccessI implements Serializable{ Bk{]g=DO
vtJJ#8a]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 DzRFMYBR
RandomAccessFile oSavedFile; pT6$DB#
long nPos; +Vdpy(
NDokSw-
9%obq/Lb
public FileAccessI() throws IOException ;8 lfOMf
{ vW@=<aS Z
this("",0); Y8t8!{ytg
} ?:9"X$XR
8zq=N#x
[{/jI\?v
public FileAccessI(String sName,long nPos) throws IOException eS){1
{ C9)@jK%
oSavedFile = new RandomAccessFile(sName,"rw"); E=O\0!F|b
this.nPos = nPos; [dVL&k<P
oSavedFile.seek(nPos); bpa?C
} 3=V&K-
'dc#F3
1Ai^cf:S
public synchronized int write(byte[] b,int nStart,int nLen) b%c9oR's^
{ cso8xq|b7
int n = -1; tfWS)y7
try{ %\:Wi#w>
oSavedFile.write(b,nStart,nLen); dqcL]e
n = nLen; @>7%qS
} WTiD[u
catch(IOException e) llDkJ)\
{ jSaU?ac
e.printStackTrace (); ;qV>L=a
} iK;XZZ(
w&.aQGR#
M D#jj3y
return n; AQ^u
} a$fnh3j[
#4;wjcGWw
qZZK#,Qb
} )QJUUn#
(**oRwr%
]eV8b*d6
/* K:WDl;8(d
**SiteInfoBean.java 'Z]w^<
*/ g0E'g
package NetFox; I]_5}[I
:rP=t ,
Zj Z^_X3
public class SiteInfoBean { iU:cW=W|M\
!bP@n
{K!)Ss
private String sSiteURL; //Site's URL o{[qZc_%
private String sFilePath; //Saved File's Path Wa~=bH
private String sFileName; //Saved File's Name 7-V/RChBm
private int nSplitter; //Count of Splited Downloading File !p/goqT~dY
.jK4?}]
tT._VK]o&R
public SiteInfoBean() Ew$C ;&9
{//nSplitter的缺省值为5 NX&_p!_V
//default value of nSplitter is 5 dQG=G%W
this("","","",5); 2 ? 4!K.
} \}G^\p6?M
.A|@?p[
:Iz8aQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) GKeU%x
{ 4 H&#q>
sSiteURL= sURL; DW3G
sFilePath = sPath; og>uj>H&
sFileName = sName; f,Ghb~y
this.nSplitter = nSpiltter; !TcJ)0
bN=P*hdf
[PbOfxxgA
} &6k3*dq
7PF%76TO
51.%;aY~z
public String getSSiteURL() fd9k?,zM
{ L\iFNT}g`
return sSiteURL; VG~Vs@c(
} KG{St{uJ
,iwp,=h=
IUct
public void setSSiteURL(String value) EBmt9S
{ nT)vNWT=
sSiteURL = value; 8JUwf
} 4`=mu}Y2
`qwBn=
+W+|%qM,\
public String getSFilePath() %xt^698&X
{ V^~:F
return sFilePath; Xlt|nX~#;
} >KKMcTOYY
tZB<on<.)
(uidNq
public void setSFilePath(String value) )=-szJjXZ
{ q" 5(H5
sFilePath = value; #)VF3T@#'
} a-J.B.A$Z/
Yz93'HDB
-D~%|).'
public String getSFileName() |vzl. ^"-
{ h@wgd~X9
return sFileName; Z5]>pJFq,
} l9H!au=
7cMv/g^h@
uXl3k:_n
public void setSFileName(String value) An/|+r\
{ 3irl (;v
sFileName = value; '/%H3A#L
} H" 7u7l
k~z Iy;AZ
g#E-pdY
public int getNSplitter() pI<f) r
{ XRQ4\bMA8
return nSplitter; 1yY0dOoLG)
} S`Rs82>
,9 a
YKf0dh;O
public void setNSplitter(int nCount) *DhiN
{ }W,[/)MO
nSplitter = nCount; UkGCyGyZ[
} {BU;$
} w@fi{H(R
(&x['IR
.6 ?U@2
/* LjHVJSC
**Utility.java vY`s'%WV
*/ Ny)X+2Ae
package NetFox; C+&l< fM&
Eu04e N
seeBS/%
public class Utility { ~4cC/"q$X
{H'Y `+
o*hF<D$Y
public Utility() Yc*;/T}
{ K\c#ig
BTrn0
;i+#fQO7Q
} 8DaL,bi*.
^sWT:BDh
//线程睡眠 o2\8OxcA
public static void sleep(int nSecond) R@rBEW&
{ d m%8K6|
try{ RViuJ;
Thread.sleep(nSecond); z*)T%p
} \1Em`nvOX
catch(Exception e) r",GC]
{ sCHJ&>m5-
e.printStackTrace (); NQ2E
} D.XvG_
} $L]lHji
~61v5@
//日志 ~W]TD@w
public static void log(String sMsg) +=8VTCn?
{ l1Fc>:o{
System.err.println(sMsg); M\Kx'N
} =_u4=4
3=ymm^
VY\&8n}e(
public static void log(int sMsg) SasJic2M
{ R{T$[$6S
System.err.println(sMsg); Xla~Yg
} 65^9
} _:27]K:
(Ep\Z 6*
!%0 *z
/* Ma"]PoP
**TestMethod.java #Mw8^FST
*/ "snw4if
package NetFox; @F*%9LPv
AYx{U?0p
)K
public class TestMethod { pyvSwD5t
HyWCMK6b
?6Y?a2 |
public TestMethod() q'82qY
{ ///xx/weblogic60b2_win.exe HHsmLo c4
try{ U4B(#2'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0lR5<^B
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); s->^=dy
SiteFileFetch fileFetch = new SiteFileFetch(bean); MFk5K
fileFetch.start(); ^gnZ+`3
} L;I]OC^J
catch(Exception e){e.printStackTrace ();} IO-Ow!
[ibu/W$
vRO _Q?
} wAW5 Z0D
@<&m|qtMsz
d/DB nZN
public static void main(String[] args) o`*,|Nsq
{ D}X\Ca"h
new TestMethod(); "#\;H$+
} w+CA1q<
} n7-6- #
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