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)); L\b_,'I
} A'-YwbY
for(int i=0;i<nEndPos.length-1;i++) `[:1!I.}-
{ YIUmCx0a
nEndPos = nStartPos[i+1]; d*(Bs$De
} i{[H3p8
nEndPos[nEndPos.length-1] = nFileLength; E/P53CD
} r_sl~^* :
} U105u.#7
u,SZ-2K!7~
xWb?i6)z&
//启动子线程 by<@Zwtf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .LcE^y[V
for(int i=0;i<nStartPos.length;i++) '<D}5u72
{ n >PM_W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), poFjhq /#(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'wlP`7&Tn
nStartPos,nEndPos,i); 7.rZ%1N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J3S+| x h~
fileSplitterFetch.start(); ayz1i:Q|
} |/\1nWD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f_2^PF>?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5nqdY*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", PlRs-%d
nEndPos = " + nFileLength); D c.WvUM
// fileSplitterFetch[nPos.length-1].start(); j=%-b]
k#NMD4(%O
cD@lorj
//等待子线程结束 pdqa)>$
//int count = 0; aMg f6veM
//是否结束while循环 J$*["y`+
boolean breakWhile = false; `2,_"9Z(
?o5#Ve$-X
@@mW+16
while(!bStop) \#7%%>p=O'
{ Riuv@i^6K
write_nPos(); TFNU+
Utility.sleep(500); y/VmjsN}
breakWhile = true; q ? TI,
M|=$~@9#X
;OqLNfU3y
for(int i=0;i<nStartPos.length;i++) .T wF]v
{ b=\3N3OX
if(!fileSplitterFetch.bDownOver) n7.lF
{ Cy'W!qH
breakWhile = false; <%uZwk>#
break; rWKLxK4oU
} k\Tm?^L)
} `9{C/qB
if(breakWhile) .h^Ld,Chj
break; I19F\ L`4
&?sjeC_
usf(U>
//count++; =C1Qo#QQ%
//if(count>4) ([o:_5/8I
// siteStop(); Y,}43a0A
} e;r-}U
D|3QLG
D ,^ U%<`
System.err.println("文件下载结束！"); ys6"Q[B
} cty#@?"e
catch(Exception e){e.printStackTrace ();} xmd$Jol^
} {\Y,UANZ
oioN0EuDk
Ps4A B#3
//获得文件长度 v~QZO4['
public long getFileSize() d}J#wT
{ wk/U"@lq
int nFileLength = -1; Q 5TyS8
try{ :u93yH6~8
URL url = new URL(siteInfoBean.getSSiteURL()); 0LuY"(LR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -z1o~~
httpConnection.setRequestProperty("User-Agent","NetFox"); V t;&2v
>m{-&1Tx
\9Zfu4WR
int responseCode=httpConnection.getResponseCode(); 7O :Gi*MA
if(responseCode>=400) Z9bPj8d
{ S]@iS[|?
processErrorCode(responseCode); K%_JQ0`
return -2; //-2 represent access is error ,{t!->K
} ?IO/zkeXg
3_-m>J**
hmk5 1
String sHeader; :Xr3 3
vtjG&0GSK
,kuOaaV7K
for(int i=1;;i++) >g=:01z9
{ sOenR6J<$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .gg0:
//Utility.log(in.readLine()); KO$8lMm$
sHeader=httpConnection.getHeaderFieldKey(i); @cNI|T
if(sHeader!=null) @},k\Is
{ L6qA=b~iz
if(sHeader.equals("Content-Length")) ;yrcH+I$_
{ ]^%3Y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); NPabM(<`
break; X~!?t}
} -W vAmi
} |8ZAE%/d
else ?"Q6;np*
break; lph_cY3p
} ?q`mr_x%?
} .1M>KRSr,
catch(IOException e){e.printStackTrace ();} "<b84?V5
catch(Exception e){e.printStackTrace ();} gRSG[GMV
H-lRgJdc
\/zS@fz
Utility.log(nFileLength); B)*%d7=x
NYRNop( N#
Os+=}
return nFileLength; 1-<Xi-=^{t
} qILr+zH
#}?$mxME*
F@3,>~[%I
//保存下载信息（文件指针位置） f}3bYF
private void write_nPos() (avaTUMOqy
{ GrIdQi^8
try{ FA,CBn5%
output = new DataOutputStream(new FileOutputStream(tmpFile)); e&nw&9vo
output.writeInt(nStartPos.length); ),|bP`V
for(int i=0;i<nStartPos.length;i++) IC~D?c0H:
{ ${3OQG
// output.writeLong(nPos); L.[2lQ
output.writeLong(fileSplitterFetch.nStartPos); hw2Hn
output.writeLong(fileSplitterFetch.nEndPos); r?*?iw2g
} d~%Rnic6*
output.close(); E ..[F<5
} g`8|jg0]`I
catch(IOException e){e.printStackTrace ();} SNFz#*
catch(Exception e){e.printStackTrace ();} $!lxVZ>
} &*~ WK
"zc!QHpSd
Rwk|cqr
//读取保存的下载信息（文件指针位置） v-qS 'N4
private void read_nPos() dRmTE
{ *z~Y*Q0
try{ p6*D^-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xa:P(x3[
int nCount = input.readInt(); >[U$n.
nStartPos = new long[nCount]; Oylw,*%
nEndPos = new long[nCount]; %yVZ|d*Q
for(int i=0;i<nStartPos.length;i++) I+SL0
{ ;2}Gqh)Yr
nStartPos = input.readLong(); iV=#'yY
nEndPos = input.readLong(); L3\{{QOA
} n\4+xZr
input.close(); AS;{{^mM(
} x&wUPo{
catch(IOException e){e.printStackTrace ();} d=XhOC$
catch(Exception e){e.printStackTrace ();} Qzv_|U
} wVTo7o%U
7Ll(,i<,C
?a}~yz#B(
private void processErrorCode(int nErrorCode) :OM>z4mQ
{ 2o;M:+KQ)
System.err.println("Error Code : " + nErrorCode); +tF,E^
} Oh: -Y]m=
_{aVm&^kA
gg9W7%t/
//停止文件下载 }sZ]SE
public void siteStop() -XBNtM_"
{ l=yO]a\QZ
bStop = true; A(B2XBS!?
for(int i=0;i<nStartPos.length;i++) as8<c4:v
fileSplitterFetch.splitterStop(); 2},}R'aR
H#D=vx'
I{$|Ed1
} <LE>WfmC
} o2L/8q.
//负责部分文件的抓取 QX4I+x~oo\
**FileSplitterFetch.java f$L5=V
*/ &nYmVwi?"Q
package NetFox; y[vjqfdmU
?/~1z*XUW
_)Ms9RN
import java.io.*; {+MMqJCa
import java.net.*; \BDNF<_
]_h"2|
Q=[&~^Y)
public class FileSplitterFetch extends Thread { FP$]D~DMo
`i-&Z`
]iPdAwc.1
String sURL; //File URL j:#[voo7
long nStartPos; //File Snippet Start Position uIu0"pv`x
long nEndPos; //File Snippet End Position @`{UiTNX`
int nThreadID; //Thread's ID >jcNo3S
boolean bDownOver = false; //Downing is over wJ}8y4O!N
boolean bStop = false; //Stop identical bCsQWsj^NW
FileAccessI fileAccessI = null; //File Access interface s`{O-
|@+ x9|'W
:;EzvRy
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Nuj%8om6
{ J_,y?}.e3
this.sURL = sURL; 8K qv)FjB
this.nStartPos = nStart; VybiuP
this.nEndPos = nEnd; @ 9uwcM1F
nThreadID = id; 0|cQx VJb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 83h6>D b
} 3yQ(,k#
t|//oEY
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public void run() _%x|,vo`(
{ {5*5tCIt
while(nStartPos < nEndPos && !bStop) ;Wr$hDt^
{ 5ZPl`[He
84k;d;
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try{ ~7*HZ:.
URL url = new URL(sURL); nV<YwqK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gr_I/+<
httpConnection.setRequestProperty("User-Agent","NetFox"); QeK~A@|F&
String sProperty = "bytes="+nStartPos+"-"; jooh`| `P
httpConnection.setRequestProperty("RANGE",sProperty); X,p&S^
Utility.log(sProperty); 4):\,>%pK
Uc&0>_Z
49CMRO,T
InputStream input = httpConnection.getInputStream(); sx9N8T3n
//logResponseHead(httpConnection); q>Y_I<;'g
?#W>^Za=
kn!J`"b
byte[] b = new byte[1024]; OIN]u{S
int nRead; (GZm+?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u3q!te
{ 7>.^GD
nStartPos += fileAccessI.write(b,0,nRead); tW,<Pe
//if(nThreadID == 1) TGg*(6'z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =U:iR
} 6Cibc.vt
}MoCUN)I
4m~\S)ad
Utility.log("Thread " + nThreadID + " is over!"); Axr'zc
bDownOver = true; !nu#r$K(
//nPos = fileAccessI.write (b,0,nRead); 6A%Y/oU+2
} '?QZ7A
catch(Exception e){e.printStackTrace ();} ]xuq2MU,l
} @sVBG']p
} -V9Cx_]y
v^e[`]u(
I%%$O'S
//打印回应的头信息 Z*JZUbo-Q
public void logResponseHead(HttpURLConnection con) U_w)*)F
{ bo]k9FC
for(int i=1;;i++) Dgdh3q;
{ qoEOM%dAqV
String header=con.getHeaderFieldKey(i); VRD2e ,K
if(header!=null) zj8;ENhEI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \PL92HV
Utility.log(header+" : "+con.getHeaderField(header)); ;Eck7nRA)
else #ujcT%1G
break; B64%| S
} #x'C
} Bs^W0K$uBO
4pF%G
9!o:)99U
public void splitterStop() O^LzS&I*
{ @%RDw*L(
bStop = true; wLW!_D,/R
} 6MZfoR
1,4kw~tA
olh|.9Kdj}
} 55hJRm3
[j&>dE
%uQ^mK
/* #B54p@.}
**FileAccess.java +&JF|#FQ`
*//文件访问(定位，写) puDy&T
package NetFox; rGx1>xd(k
import java.io.*; (R.k.,z
sjztT<{Q^-
o6'`W2P
public class FileAccessI implements Serializable{ @UD6qA
xJ,V!N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {<&x9<f9
RandomAccessFile oSavedFile; T?Gi;ld7
long nPos; U%2pbGU
^M8\ 3G
>:8GU f*
public FileAccessI() throws IOException ^8B#-9Ph b
{ KWM.b"WnXr
this("",0); nJrV
} oU67<jq
AM\`v'I*6
1Hzj-u&N/
public FileAccessI(String sName,long nPos) throws IOException <` HLG2
{ 'j>Q7M7q{
oSavedFile = new RandomAccessFile(sName,"rw"); )0!hw|0|
this.nPos = nPos; %$S.4#G2
oSavedFile.seek(nPos); i |cSO2O+
} XYf;72*
?f:FmgQk
_^Rf*G!
public synchronized int write(byte[] b,int nStart,int nLen) vfmKYiLp
{ E+csK*A7
int n = -1; Ws'3*HAce
try{ i $#bg^
oSavedFile.write(b,nStart,nLen); 9CW .xX8
n = nLen; .DIHd/wA
} I9TOBn|6
catch(IOException e) `2 Z
{ Q_]O[Kx
e.printStackTrace (); jg' 'T1)
} 0lY.z$V
iw<+rh*C
J$@3,=L6V
return n; -&%#R_RV
} {'EQ%H$q
0t'WM=W<!8
n`;=^^B
} "m(HQ5e)*
=[3I#s?V
kznmA`#jn
/* Tj@s\@hv
**SiteInfoBean.java B!yAam#^
*/ NkA|T1w7
package NetFox; O~Pbu[C
?tg(X[h{S
7l%O:M(\
public class SiteInfoBean { (?;Fnq
x~Y]c"'D
,accw}G
private String sSiteURL; //Site's URL tBp dKJn##
private String sFilePath; //Saved File's Path %Gh!h4Pv
private String sFileName; //Saved File's Name utfD$8UI
private int nSplitter; //Count of Splited Downloading File H~Hh$-z
u6$fF=
>@`D@_v
public SiteInfoBean() ]t(;bD hT
{//nSplitter的缺省值为5 \k;*Ej~.
//default value of nSplitter is 5 rt^<=|Z
this("","","",5); !ku5P+y$
} [r<lAS{ .
ldO6W7G|h
c"H*9u:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gfR B
{ WfL5.&
sSiteURL= sURL; u#ag|b/C:
sFilePath = sPath; d*4fl.
sFileName = sName; {?$-p%CF`8
this.nSplitter = nSpiltter; Vd1.g{yPV
?1JS*LQ$
DgGGrV`
} now\-XrS
3mIVNT@S9
T&j_7Q\;vI
public String getSSiteURL() "at*G>+
{ %nSLe~b
return sSiteURL; S{XV{o
} &>XIK8*
eZ8~t/8
^~E?7{BL
public void setSSiteURL(String value) !/[/w39D0o
{ Mnn\y Tblp
sSiteURL = value; ckHHD|
} h}nceH0s3d
mhv{6v
2zZ" }Zr#
public String getSFilePath() Wz`MEyj
{ Hw-,sze j"
return sFilePath; |W[BqQIf
} 3){ /u$iH.
Xb@lKX5Re
"u@)
public void setSFilePath(String value) 82O#Fe q
{ /4}{SE
sFilePath = value; 07:CcT
} oj/,vO:QT
_VFl.U,
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public String getSFileName() $DuX1T
{ 4Z.G
return sFileName; tF}Vs}
} IV]s!
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]2`PS<a2
public void setSFileName(String value) X~(%Y#6
{ 3C=ON.1eg
sFileName = value; ~G+o;N,V
} qv>?xKSm
wxYB-Wh<
$[x2L s~
public int getNSplitter() zZ@]Kq;.s
{ 2ys'q!
return nSplitter; aY&He~
} @8a1a3_F
|1iCt1~U
z~i=\/~tZ
public void setNSplitter(int nCount) Yx>y(Whu.
{ 16Ym*kWIps
nSplitter = nCount; {x$jGiag+8
} ;-Fr^|do y
} C]59@z;+bN
E2+x?Sc+
)4q0(O)d
/* I CCmE#n
**Utility.java E`]lr[
*/ KV v0bE
package NetFox; c'ExZ)RJ
J\VG/)E
^LO=&Cq
public class Utility { {y-7xg~}
f_y+B]?'M
G9"2h \
public Utility() x;w&JS1V
{ *8ykE
XaOq&7
ig(dGKD\=9
} /G[; kR"
j5QS/3
//线程睡眠 ZU\TA|
public static void sleep(int nSecond) mVUDPMyZ
{ VbQ9o
try{ }g6:9%ZMu
Thread.sleep(nSecond); A&u"NgJ
} l8rBp87Q
catch(Exception e) 'Pyeb`AXE9
{ z'FD{xdf
e.printStackTrace (); s2s}5b3
} `hJSo?G>
} WPLM*]6
=I. b2e1z
//日志 OY$P8y3MY
public static void log(String sMsg) ?fF{M%i-%
{ 0tV"X
System.err.println(sMsg); doM}vh)6
} `uK_}Vy_
~Mu=,OT
;/.ZjTRw
public static void log(int sMsg) LU "e9
{ 9*wS}A&Jh
System.err.println(sMsg); pI*/-!I
} c}(fmJB&(
} ,2hZtJ<A
mNUc g{+/
(5AgI7I,
/* Ewg5s?2|
**TestMethod.java A#t#c*
*/ e+J|se4L5
package NetFox; cu&tdg^q
--Dd'
T 9lk&7W
public class TestMethod { A'(v]w
U-+%e:v
uEp v l
public TestMethod() /Hxz@=LC1
{ ///xx/weblogic60b2_win.exe v"x{oD$R
try{ ;533;(d*o
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); j(JUOief
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +Ja9p
SiteFileFetch fileFetch = new SiteFileFetch(bean); 38(Cj~u=3
fileFetch.start(); 0>PO4WFVJ
} &Z Ja}5k!r
catch(Exception e){e.printStackTrace ();} ?Uz7($}
'J*)o<%
QvB]?D#h
} tTa" JXG
,1>ABz
L\p@1N?K
public static void main(String[] args) uYk4qorA
{ doJ\7c5uU
new TestMethod(); MN|8(f5Gs
} z>_jC+
} P8#;a
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