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)); yD7BZI xW
} ;-+q*@sa]
for(int i=0;i<nEndPos.length-1;i++) or/gx3
{ zx3gz7>k;
nEndPos = nStartPos[i+1]; ^7-zwl(>?N
} CL|/I:%0
nEndPos[nEndPos.length-1] = nFileLength; c$O8Rhx
} ,o&C"sb
} S#7YJ7 K"N
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\$ytmtf5
//启动子线程 <$A,Ex94
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; c0qp-=^&.
for(int i=0;i<nStartPos.length;i++) fpD$%.y'J
{ 54gr'qvr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Zw.8B0W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7>FXsUt_
nStartPos,nEndPos,i); =<HDek
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ld4U
fileSplitterFetch.start(); UB/> Ro
} ZJYn[\]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Qp>leEs]+6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CU'JvVe3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l~c[}wv
nEndPos = " + nFileLength); Zxa.x?:?n
// fileSplitterFetch[nPos.length-1].start(); t`Kbm''d[
6b2UPI7m~
szI7I$Qb
//等待子线程结束 M/zO|-j&
//int count = 0; ,_2-Op
//是否结束while循环 T5S4,.o9W
boolean breakWhile = false; Yj%]|E-
a.Ho>(V/4
3JCo!n0
while(!bStop) ]&cnc8tC
{ :xd;=;q5
write_nPos(); . %RM8
Utility.sleep(500); b)LT[>f
breakWhile = true; L:z0cvn"
ag-A}k>v
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for(int i=0;i<nStartPos.length;i++) o NtFYY
{ : T*Q2
if(!fileSplitterFetch.bDownOver) BOs/:ZbK0W
{ LG #^g6P
breakWhile = false; /^.|m3
break; KZm&sk=QM-
} _yg_?GH
} ^L[:DB{Z
if(breakWhile) 2jsbg{QS#_
break; *FlPGBjJ
"6B7EH
$v^hzC
//count++; -@orIwA&
//if(count>4) %TB(E<p`
// siteStop(); Sc)^k
} _?{7%(C
JJ?{V:
Ei;tfB
System.err.println("文件下载结束！"); ([>ecS@eO
} z _!ut
catch(Exception e){e.printStackTrace ();} ARk(\,h
} %opBJ
xoaO=7\io
+$2{u_m,
//获得文件长度 S;|:ci<[=
public long getFileSize() /jbAf]"F;
{ ?t#wK}d.
int nFileLength = -1; ?#xl3Z ;I
try{ sX>u.
URL url = new URL(siteInfoBean.getSSiteURL()); 9d(\/ 7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h^M_yz-f
httpConnection.setRequestProperty("User-Agent","NetFox"); bGRt
qQ@| Cj
WK~H]w
int responseCode=httpConnection.getResponseCode(); hW^,' m
if(responseCode>=400) x7j#@C
{ %)ho<z:7U
processErrorCode(responseCode); K,b M9>}
return -2; //-2 represent access is error 3DU1c?M:
} Ndmt$(b
Fn4v/)*H
04a ^jjc
String sHeader; aSL`yuXu
1+l8%G=hB
u-_r2U
for(int i=1;;i++) Hbm 4oYN
{ _;lw,;ftA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tFN >]`Z
//Utility.log(in.readLine()); dzVi ~wt_&
sHeader=httpConnection.getHeaderFieldKey(i); U|^xr~q!f-
if(sHeader!=null) $=aO*i
{ @6u/)>rI
if(sHeader.equals("Content-Length")) 7|rH9Bc{U
{ tne_]+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %,>z`D,Hg
break; h ><Sp*z_V
} E$8JrL
} mxc)Wm<4
else Q7%4`_$!
break; b 2gng}
} h Yu6PWK
} Z;0~f<e%
catch(IOException e){e.printStackTrace ();} X{9^$/XsJ
catch(Exception e){e.printStackTrace ();} q z)2a2C
a#oROb-*~
Fr%#
Utility.log(nFileLength); ! 'zd(kv<
T$Z9F^w
TpjiKM
return nFileLength; m]p{]6h
} Q*ITs!~Z
\pmS*Dt
wxN)dB
//保存下载信息（文件指针位置） (In{GA7;
private void write_nPos() f/Gx}x=
{ 53Adic
try{ &L o TO+
output = new DataOutputStream(new FileOutputStream(tmpFile)); o%d TcoCN
output.writeInt(nStartPos.length); @s5=6z]=H
for(int i=0;i<nStartPos.length;i++) eP{srP3 9
{ J-W9Bamx
// output.writeLong(nPos); ^-o{3Q(w
output.writeLong(fileSplitterFetch.nStartPos); /:dLqyQ_V
output.writeLong(fileSplitterFetch.nEndPos); }nmlN
} 2YD\KXDo
output.close(); iFI74COam
} n1[c\1
catch(IOException e){e.printStackTrace ();} t],a1I.gk
catch(Exception e){e.printStackTrace ();} <_?zln:4.
} j,IRUx13f
!MbzFs~
[%W'd9`>
//读取保存的下载信息（文件指针位置） 86&M Zdv6
private void read_nPos() KK|w30\f
{ 1wSAwpz
try{ NvK9L.K
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); EF/d7
int nCount = input.readInt(); {X{R]
nStartPos = new long[nCount]; C.j+Zb1Z(
nEndPos = new long[nCount]; KE?t?p
for(int i=0;i<nStartPos.length;i++) ,'L>:pF3
{ PyeNu3Il4
nStartPos = input.readLong(); 6[bopin
nEndPos = input.readLong(); *TOdIq&z
} .i0K-B
input.close(); kpOdyn(
} 5LeZ?'"c
catch(IOException e){e.printStackTrace ();} *k?:k78L
catch(Exception e){e.printStackTrace ();} E)b$;'
} _&KqmQ8$7
awLvLkQb{
H MOIUd
private void processErrorCode(int nErrorCode) P^Hgm
{ ~ |G&cg
System.err.println("Error Code : " + nErrorCode); lg%fjBY
} Vaxg
!-I,Dh-A
DE13x*2
//停止文件下载 I8#2+$Be+@
public void siteStop() e=amh
{ ns[/M~_r
bStop = true; 5eAZfe%H
for(int i=0;i<nStartPos.length;i++) UmKE]1Yw4r
fileSplitterFetch.splitterStop(); I}$`gUXX8x
'|yxB')
(P>nA3:UXB
} *,u3Wm|7
} 2=cx`"a$
//负责部分文件的抓取 +LHU}'|
**FileSplitterFetch.java c r=Q39{
*/ 1(' wg!
package NetFox; %-hSa~20
uWS]l[Ga
)Q2Ap&
import java.io.*; t~2oEwTm
import java.net.*; f\&X$g
?G{0{c2
>t+ ENYb
public class FileSplitterFetch extends Thread { &61U1"&$R
lZzW- %K
)@]%:m!ER
String sURL; //File URL 7w )?s@CD
long nStartPos; //File Snippet Start Position d<c29Y
long nEndPos; //File Snippet End Position Omd;
int nThreadID; //Thread's ID ss^a=?~
boolean bDownOver = false; //Downing is over RhYe=Qh4{p
boolean bStop = false; //Stop identical k@xinK%O{
FileAccessI fileAccessI = null; //File Access interface EKc<|e,F
.jRI $vm
aIgexi,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =%_=!%
{ b42%^E
this.sURL = sURL; ;@+|]I
this.nStartPos = nStart; FgdnX2s J
this.nEndPos = nEnd; cXXZ'y>FP
nThreadID = id; -"-.Z&#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,fjY|ip
} Qt u;_
rrIyZ@_d9
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public void run() hs6pp/h>
{ M+"6VtZH
while(nStartPos < nEndPos && !bStop) #p+iwW-
{ HDm]njF%qQ
2gWR2 H@
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try{ 9qX$
URL url = new URL(sURL); YS3~sA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WZa6*pF
httpConnection.setRequestProperty("User-Agent","NetFox"); -TD\?Q
String sProperty = "bytes="+nStartPos+"-"; }L0 [Jo:
httpConnection.setRequestProperty("RANGE",sProperty); (bm^R-SbB
Utility.log(sProperty); MqJTRBs%
Zo UeLU
B*/!s7c.
InputStream input = httpConnection.getInputStream(); DG&'x;K"$
//logResponseHead(httpConnection); 8Qi)E1n
}$oS/bo
c[2t,+O
byte[] b = new byte[1024]; 3ynkf77cn
int nRead; |bk9<i ?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~[=<Os
{ S1|5+PPs
nStartPos += fileAccessI.write(b,0,nRead); `%YMUBaI
//if(nThreadID == 1) |s3;`Nxu7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m|NZ093d
} u|KjoO
Na@bXcz)
Z?P^Y%ls
Utility.log("Thread " + nThreadID + " is over!"); jCY~Wc
bDownOver = true; 9]Jv >_W*
//nPos = fileAccessI.write (b,0,nRead); tE%g)hL-
} AojL4H|
catch(Exception e){e.printStackTrace ();} y\v#qFVOZ
} ~\=D@G,9
} 7U7!'xU
;R=n<=Axa
re*Zs}(N\
//打印回应的头信息 'VVU-)(8
public void logResponseHead(HttpURLConnection con) 6B]=\H
{ |!FQQ(1b
for(int i=1;;i++) ?I]AE&4'
{ DE.].FD'
String header=con.getHeaderFieldKey(i); R;HE{q[ f
if(header!=null) v4e4,Nt
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z9:
Utility.log(header+" : "+con.getHeaderField(header)); AL":j6!OQ
else 20I`F>-*
break; 2]kGDeSr
} k"#gSCW$
} 4?Y7.:x
ILr=<j
1;[KBYUH
public void splitterStop() +cfcr*
{ 8SpG/gl"
bStop = true; { <Gyjq
} pZ8J\4+
G:*vV#K
OROvy
} $e1.y b%
9(t(sP_
pPa]@ z~O
/* .B~}hjOZK
**FileAccess.java B*_K}5UO
*//文件访问(定位，写) gaN/ kp
package NetFox; uD/@d'd_4L
import java.io.*; z5gVP8*z5
UvGxA[~2+
WVD48}HF-
public class FileAccessI implements Serializable{ yKhI&
z~2{`pET
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W=HvMD
RandomAccessFile oSavedFile; XaCvBQ
long nPos; r10VFaly
5Pf=Uj6D
o2dO\$'
public FileAccessI() throws IOException 7;+G)44
{ Hc\C0V<
this("",0); UYxn?W.g
} a/uo)']B
%Bw:6Y4LZ
xc*a(v0
public FileAccessI(String sName,long nPos) throws IOException q\@_L.tc[
{ (zFqb,P
oSavedFile = new RandomAccessFile(sName,"rw"); Mf14> `<`
this.nPos = nPos; wU|@fm"
oSavedFile.seek(nPos); #czTX%+9(e
} A|LO!P,w
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6D Xja_lp
public synchronized int write(byte[] b,int nStart,int nLen) S'5)K
{ /e"iYF
int n = -1; WzstO}?P(
try{ inh:b .,B
oSavedFile.write(b,nStart,nLen); XB7*S*"!
n = nLen; 46]BRL2 G
} Iuz_u2"C
catch(IOException e) ~*bfS}F8I
{ /[dMw *SRz
e.printStackTrace (); p _[,P7
} FzEs1hpl
9287&+,0r
{@CQ (
return n; -+{[.U<1jk
} l<XYDb~op
ntLEk fK{
8\68NG6o
} H?O5 "4a
6!>p<p"Ns
XfE0P(sE
/* %SB4_ r*<
**SiteInfoBean.java PwW$=M{\.
*/ Xk.OyQ@
package NetFox; K ,NmDc^
8Azh&c
,r*Kxy
public class SiteInfoBean { EF!J#N2
1N(#4mE=
L9O;K$[s
private String sSiteURL; //Site's URL N `:MF 9
private String sFilePath; //Saved File's Path Yw#fQFm
private String sFileName; //Saved File's Name _%R^8FjH*
private int nSplitter; //Count of Splited Downloading File +r'&6Me!
kf>3T@
8OZasf
public SiteInfoBean() =q0V%h{
{//nSplitter的缺省值为5 ( 0/M?YQF
//default value of nSplitter is 5 i=\)[;U
this("","","",5); QTBc_Z
} VOD-< "|
Soq#cl'll-
<qfAW?tF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %W9R08`
{ ~<!j]@.
sSiteURL= sURL; %JrZMs>
sFilePath = sPath; w^Y/J4 I0
sFileName = sName; R/x3+_.f
this.nSplitter = nSpiltter; ZeuL*c \
AE>W$x8P
Bk\Y v0
} Wz.iDRFl
w\s`8S
:se$<d%
public String getSSiteURL() 0F-{YQr>
{ =s":Mx,o
return sSiteURL; rlR!Tc>
} (9RfsV4^
7:olStK
,93Uji[l
public void setSSiteURL(String value) LUD.
{ Fn.JtIu
sSiteURL = value; ;+XrCy!.)L
} J@:Q(
B?i#m^S
'y;Kj
public String getSFilePath() s>o#Ob@4'
{ )KE
return sFilePath; &*>.u8:r
} :.ZWYze
h"+7cc@
*Z"`g %,;
public void setSFilePath(String value) &PE%tm
{ Lq5xp<
sFilePath = value; 60^j<O
} -B#1+rUW
WGn=3(4
'Z~ZSu
public String getSFileName() pZ'q_Oux
{ enJ;#aA
return sFileName; Qwpni^D8j
} uQ-GJI^t
(*$F7oO<
2pdeJ
public void setSFileName(String value) FShjUl>mV
{ I;NW!"pU
sFileName = value; Ur#jJR@%3
} +Mq\3
P4Pc;8T@!
N\*oL*[j
public int getNSplitter() <b H*f w
{ nC p/.]Y*
return nSplitter; k!x|oC0
} =KHb0d |.
@CzFzVmF"
]S4"JcM
public void setNSplitter(int nCount) 0\XWdTj{
{ xg/(
nSplitter = nCount; 7*uN[g#p
} %urvX$r4K
} ^}Vc||S
neM.M)0
c`;oV-f
/* ~'lT8 n_
**Utility.java IOZw[9](+
*/ aI&~aezmN
package NetFox; `hO%(9V9
56z>/`=
?@4Mt2Z\
public class Utility { AB/${RGf+
|K1S(m<F
a6n@
public Utility() 0RA#Y(IR
{ xR0*w7YE
_">F]ptI;
tV(iC~/
} 76rv$z{g^
yS~Y"#F!.
//线程睡眠 @/kI;8
public static void sleep(int nSecond) ]:Ep1DIMl
{ K9EHT-
try{ e2c'Wab
Thread.sleep(nSecond); MS;^:t1`
} d]e36Dwk
catch(Exception e) <8 <P,
{ V.:,Q
e.printStackTrace (); )!27=R/
} 2*V%S/cck
} dPu27 "
bs|gQZG
//日志 E7/UsUV.
public static void log(String sMsg) 8*u'D@0
{ ;GM`=M4
System.err.println(sMsg); )1Bz0:
} C`[2B0
C{/U;Ie-b
#).^k-
public static void log(int sMsg) o4p5`jOG@
{ hx0t!k(3
System.err.println(sMsg); zgjgEhnvU
} Wd7*7']
} Z0Sqw
6<W^T9}v@/
$V3If
/* \@Cz 32wg
**TestMethod.java Q.$8>)
*/ {2q"9Ox"
package NetFox; (9]1p;
9e`};DE
VQ('ejv}/
public class TestMethod { xMk>r1Ud
RjVUm+<
(.N n|lY<i
public TestMethod() `/T.u&QF
{ ///xx/weblogic60b2_win.exe ~s&r.6DW
try{ v+x<X5u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MMrN#&r
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); EgG3XhfS
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4Mg%}/cC
fileFetch.start(); vGsAM*vw6
} -sv%A7i
catch(Exception e){e.printStackTrace ();} *^@b0f~vj
cRKLyb
G!VEV3zT
} ^/?7hbr
]+,L/P
[H\0 '
public static void main(String[] args) 3.dSS
{ O+mEE>:w%
new TestMethod(); ^(
} 92Gfxld\
} x$jLB&+ICz
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