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)); [:B*6FXMN~
} 88o:NJ}_
for(int i=0;i<nEndPos.length-1;i++) m UgRm]
{ }N,>A-P
nEndPos = nStartPos[i+1]; m =k%,J_
} ;J=:IEk
nEndPos[nEndPos.length-1] = nFileLength; l &Z(K,6
} ik\S88|
} o^GC=Aca`
Z %EQt
#{,h@g}W
//启动子线程 >FF1)~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rBfg*r`)
for(int i=0;i<nStartPos.length;i++) w+_Wc~f
{ hk;bk?:m
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j@v-|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D9o*8h2$
nStartPos,nEndPos,i); ikHOqJ-,m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D]u=PqHk2
fileSplitterFetch.start(); x)R0F\_
} 9L"?wv
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .Dx2 ;lj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); K)5;2lN,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 968^"T#
nEndPos = " + nFileLength); ) b:4uK A
// fileSplitterFetch[nPos.length-1].start(); `~nCbUUee
rPO}6lsc
|-61(X.
//等待子线程结束 bl.EIyG>
//int count = 0; 38wq (
//是否结束while循环 kl<g;3
boolean breakWhile = false; >{XScxaB`
xb`CdtG2.
j38 6gL
while(!bStop) 7K:FeW'N
{ ,8VXA +'_
write_nPos(); yVYkuO
Utility.sleep(500); >76 |:Nq
breakWhile = true; [YE?OQ7#
s<VJ`Ur
LyP`{_"CM
for(int i=0;i<nStartPos.length;i++) a}yR p
{ o?\Gm
if(!fileSplitterFetch.bDownOver) UABbcNW
{ #(dhBEXPW;
breakWhile = false; Q>%E`h
break; o9+Q{|r
} !I7?
} %zflx~
if(breakWhile) OG}KqG!n
break; ?O7iK<5N
kfK[u/<i
(9'be\
//count++; 4(|yD;
//if(count>4) 0BDS_Rx
// siteStop(); pVz*ZQ[]
} PWG;&ma
{(0Id!
fTgbF{?xh
System.err.println("文件下载结束！"); tqhh<u;
} '!@A}&]
catch(Exception e){e.printStackTrace ();} 8Fx]koP.
} |^!Vo&T
/.@x 4cdS
?Cc :)
//获得文件长度 3):?ZCw7y
public long getFileSize() ^O \q3HA_4
{ :D4];d>1
int nFileLength = -1; 5M.Red.L
try{ DaDUK?
URL url = new URL(siteInfoBean.getSSiteURL()); O! (85rp/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #JFYws
httpConnection.setRequestProperty("User-Agent","NetFox"); GhiHA9.
l7~Pa0qD
%I}'Vb{C
int responseCode=httpConnection.getResponseCode(); hXTYTbTX
if(responseCode>=400) Om6Mmoqh
{ 5p{25N_t
processErrorCode(responseCode); eA&t%
return -2; //-2 represent access is error wPQ&Di*X}
} 6VFirLd
X2{`l8%Ek
"$P'Wv
String sHeader; %2YN,a4
v^\JWPR/
DZ2Fl>7
for(int i=1;;i++) ydyG}XI7V
{ cdDY]"k
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); SctJxY(}!
//Utility.log(in.readLine()); 1yJ75/
sHeader=httpConnection.getHeaderFieldKey(i); SdSgn|S
if(sHeader!=null) &t_A0z
{ ,zoB0([
if(sHeader.equals("Content-Length")) I}_;A<U
{ R` 44'y|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?(>k,[n
break; 1wlVz#f.
} z2v<a{e
} Q-3r}jJe
else WV@X@]U
break; Qxky^:B
} e`;t<7*i
} yIWc\wv
catch(IOException e){e.printStackTrace ();} 7|{ B#
catch(Exception e){e.printStackTrace ();} "R8.P/ 3
{=qEBbM
[bsXF#
Utility.log(nFileLength); T:6K?$y?
`ReGnT[
9p4%8WhJ
return nFileLength; X0!Bs-WFp
} Enu!u~1]F
F$[)Bd/"
v` $%G
//保存下载信息（文件指针位置） W oWBs)E
private void write_nPos() HmW=t}!
{ <c(&T<$
try{ _TrZ'iL}T
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8<Xq=*J+
output.writeInt(nStartPos.length); }a'cm!"
for(int i=0;i<nStartPos.length;i++) .Jptj
{ gU+ss
// output.writeLong(nPos); WqR7uiCi
output.writeLong(fileSplitterFetch.nStartPos); el}hcAY/RP
output.writeLong(fileSplitterFetch.nEndPos); X:U=MWc>
} tg3zXJ4k_
output.close(); [z^Od
} !ZX&r{pJp
catch(IOException e){e.printStackTrace ();} o>.AdZby
catch(Exception e){e.printStackTrace ();} 2G ZF/9}
} r1+c/;TpZ
9uKOR7.zbo
D/e&7^iK
//读取保存的下载信息（文件指针位置） iQu^|,tHEM
private void read_nPos() |^?`Q.|c$
{ <>VIDE
try{ Qg[heND
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b$dBV}0 L
int nCount = input.readInt(); 8>ESD}(
nStartPos = new long[nCount]; xC'mPcU8
nEndPos = new long[nCount]; q)vK`\Y
for(int i=0;i<nStartPos.length;i++) )sRN!~
{ (v]P<3%
nStartPos = input.readLong(); U&`6&$]
nEndPos = input.readLong(); 5[nmP95YK
} Wux0RF&
input.close(); lK "'nLL
} gAj0ukX5
catch(IOException e){e.printStackTrace ();} tB]`Hj
catch(Exception e){e.printStackTrace ();} :-(U%`a[
} ~KJ,SLzhx9
UE\%e9<l
cT\Ov P*_
private void processErrorCode(int nErrorCode) K!9y+%01
{ DE'Xq6#PK
System.err.println("Error Code : " + nErrorCode); 3'.! +#
} HJc<Gwm
fn3*2
Ob7zu"zr
//停止文件下载 L^6"'#
public void siteStop() 1X[73
{ w8G7Jy
bStop = true; LFl2uV"
for(int i=0;i<nStartPos.length;i++) BQ).`f";d
fileSplitterFetch.splitterStop(); :sU!PF[<
d:A\<F
^g}L`9fL
} rFf:A-#l
} hJecCOA)'
//负责部分文件的抓取 >9 q]>fJ
**FileSplitterFetch.java G!nl'5|y
*/ )t*S'R
package NetFox; <}<#W/
km9Gwg/zT
SRP5P,-y
import java.io.*; nWKO8C>
import java.net.*; "(Mvl1^BT
>s;oOo+5
izXbp02
public class FileSplitterFetch extends Thread { ${wU+E*
Y,3z-Pa=@
(irk$d %
String sURL; //File URL Dq{:R
long nStartPos; //File Snippet Start Position ~&t!$
long nEndPos; //File Snippet End Position {k kAqJ
int nThreadID; //Thread's ID lt }r}HM+
boolean bDownOver = false; //Downing is over -b@v0%Q2M*
boolean bStop = false; //Stop identical E7V38Z
FileAccessI fileAccessI = null; //File Access interface MomLda V9Q
_TtX`b_Z
-b].SG5S
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \El|U#$u'
{ YI L'YNH
this.sURL = sURL; N<p5p0
this.nStartPos = nStart; AmP#'U5
this.nEndPos = nEnd; ue,#,3{m
nThreadID = id; -L+\y\F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OD{5m(JwL
} PthIdaN@
;7;zhJs1t
n/ui<&(
public void run() {CW1t5$*
{ 0eQ~#~j&
while(nStartPos < nEndPos && !bStop) 3"^a rK^N
{ M' &J_g
~sZqa+jB0
`6|i&w:b
try{ l R:Ok8e
URL url = new URL(sURL); t.3Ct@wK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s]$HkSH
httpConnection.setRequestProperty("User-Agent","NetFox"); lo\:]/&6
String sProperty = "bytes="+nStartPos+"-"; 6\; 4 4,3
httpConnection.setRequestProperty("RANGE",sProperty); ;M%oQ>].[
Utility.log(sProperty); m\<<oIlH
l0qdk#v
pYYqGv^oa
InputStream input = httpConnection.getInputStream(); kqj;l\N
//logResponseHead(httpConnection); <8}KEe4
k)?,xY\AV
&?P=arU
byte[] b = new byte[1024]; .}IK}A/-
int nRead; >+yqjXRzm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) F% F c+?
{ Fg_?!zR>6
nStartPos += fileAccessI.write(b,0,nRead); K<$wz/\
//if(nThreadID == 1) It#hp,@e
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !F=|*j
} `'z(--J}`
\hjk$Gq
|pfhrwJp
Utility.log("Thread " + nThreadID + " is over!"); >t1_5
bDownOver = true; QH@Q\ @,
//nPos = fileAccessI.write (b,0,nRead); fG:PdIJ7_
} Xz;et>UD*B
catch(Exception e){e.printStackTrace ();} .OVW4svX
} lcu("^{3
} FQ;4'B^k]
<dju6k7uz
;cM8EU^.
//打印回应的头信息 1x~%Ydy
public void logResponseHead(HttpURLConnection con) $sA,$x:^xI
{ 8[6ny=S`
for(int i=1;;i++) 7Vz[ji
{ 2rK-X_}
String header=con.getHeaderFieldKey(i); !^c:'I>~
if(header!=null) .8u$z`j
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d$2@,
Utility.log(header+" : "+con.getHeaderField(header)); [VY8?y
else &/b?I `
break; Nrab*K(][
} ET >S
} Z!C`f/h9
$nUd\B$.=
6{JR0
public void splitterStop() k#1`
{ Jngll
bStop = true; D8r>a"gx
} P<j4\zJ
&{-oA_@
M/::`yJQu
} Hs:4I
{:};(oz)f
k| _$R?
/* '1>g=Ic0
**FileAccess.java ua]\xBWx
*//文件访问(定位，写) (SgEt
package NetFox; %JP&ox|^&
import java.io.*; (cOND/S
`c qH}2s#
9_M H
public class FileAccessI implements Serializable{ JcvHJ0X~a
]FY?_DGOA
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 u)q2YLK8
RandomAccessFile oSavedFile; e3yorQ][
long nPos; 5PPPd-'Z_
_H~pH7WU
@Og\SZhn
public FileAccessI() throws IOException @{J!6YGh
{ N.fQ7z=Z(M
this("",0); "e1{V8 4
} hj^G}4
E5,%J
P?Gd}mdX?m
public FileAccessI(String sName,long nPos) throws IOException `^XRrVX<
{ x'E'jh%
oSavedFile = new RandomAccessFile(sName,"rw"); [?|l X$<
this.nPos = nPos; lKh2LY=j
oSavedFile.seek(nPos); Q%,o8E2~
} nZ2mEt
fWtb mUq
A&NC0K}G!
public synchronized int write(byte[] b,int nStart,int nLen) D\45l
{ ifJv~asp
int n = -1; w%i+>\tO
try{ X_-Hrp!h
oSavedFile.write(b,nStart,nLen); rE1np^z7
n = nLen; cM> G>Yzo
} ! /|0:QQi
catch(IOException e) #hy5c,}>
{ ugIm:bg&
e.printStackTrace (); 38x[Ad4%
} ^D]7pe
Z`-)1!
^F0k2pB
return n; 2- Npw%;
} j:rs+1bc
"W?l R4
x*,q Rew
} Hm+6QgCs
ZXssvjWQV}
4*N@=v
/* |kBg8).B
**SiteInfoBean.java r)9i1rI+
*/ _g^K$+F'}
package NetFox; CI~hmL0
wS F!Xx0
#K<=xP
public class SiteInfoBean { uZqu xu.
qHC*$v#.V?
SHXa{-
private String sSiteURL; //Site's URL 0,vj,ic*WX
private String sFilePath; //Saved File's Path SxLHFN]
private String sFileName; //Saved File's Name r 48;_4d)D
private int nSplitter; //Count of Splited Downloading File q_9N+-?{7
nK?k<
DU*g~{8T$
public SiteInfoBean() .v #0cQX+.
{//nSplitter的缺省值为5 8T>3@kF
//default value of nSplitter is 5 y]QQvCJr3d
this("","","",5); |*]X\UE
} zCj*:n
=#POMK".6
((RpT0rP\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #whO2Mv
{ &dZ.+#8r
sSiteURL= sURL; y]E)2:B[d
sFilePath = sPath; UijuJ(Tle
sFileName = sName; !~|"LA!jn
this.nSplitter = nSpiltter; 9AVK_
$.r}g\43P
K*HVn2OV
} HonAK
"EOk^1,y
eSvc/CU
public String getSSiteURL() ;4S [ba1/
{ ?v)"%.
return sSiteURL; $X.'W\o|
} (zM+7tJH
43}&w.AS
(<>Sz(
public void setSSiteURL(String value) C~ }Wo5
{ xdbu|fC
sSiteURL = value; BZ\EqB
} |$.sB|_ N
ZaNyNxbp>z
5Re`D|8
public String getSFilePath() R uFu,H-
{ U47k5s(J
return sFilePath; %T,\xZ
} %`s9yRk9>E
,h wf
',J%Mv>Yf
public void setSFilePath(String value) -?%{A%'
{ M$>WmG1~D
sFilePath = value; wNf*/?N
} g`~lIt[=
mISuo
rvoS52XG,
public String getSFileName() W(PW9J9
{ &>) `P[x
return sFileName; A\PV@w%Ai
} .f.j >
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qG2\`+v
public void setSFileName(String value) E3.W#=o
{ e~2*>5\:
sFileName = value; y?R <g^A
} .U(SkZ`6
-fSKJo#}|
k.? T.9
public int getNSplitter() 8tFyNl`c
{ d~z<,_r5c
return nSplitter; 7zP
} /xrq'|r?C
/J9T=N
"` ?Wu
public void setNSplitter(int nCount) rfZj8R&
{ RQK**
nSplitter = nCount; whg4o|p
} bcx{_&1p
} <1'X)n&Kw$
5f`XFe$8
cnUU1Uz>
/* Nh7!Ah
**Utility.java -)vp&-
*/ n]ppO U|[
package NetFox; ]BS{,sI
We+FP9d%
;u-< {2P
public class Utility { kAQ\t?`x
Vp-OGX[
cwW~ *90#
public Utility() -m x3^
{ n5,Pq+[
yg[Oy#^
hk$nlc|$
} 9jzLXym
CyBM4qyH
//线程睡眠 23n8,} H,
public static void sleep(int nSecond) * SON>BSF
{ Kp=3\)&
try{ $d??(
Thread.sleep(nSecond); )i6U$,]
} $b 71
catch(Exception e) . =foXN
{ 9q,JqB
e.printStackTrace (); |Nd.'|g,
} JU%yqXO
} 5tCq}]q#P
m{yNnJ3O
//日志 "y ,(9_#
public static void log(String sMsg) Nxs%~wZ
{ ThQEQ6y
System.err.println(sMsg); Ynh4oWUp
} {^19.F
kA:;c}p
L!8?2 \5
public static void log(int sMsg) W2.1xNWO
{ 6pz:Lfd80
System.err.println(sMsg); A[,"jh
} ?yM/j7Xn
} K'rs9v"K|
U+A(.+d.
PQ#-.K
/* ]A<u eM
**TestMethod.java fF]&{b~wk
*/ <.%8j\j(
package NetFox; i.dAL)V
P:h4
Y&Vbf>Hi+
public class TestMethod { T^H) lC#R
GDQg:MgX
vc1GmB
public TestMethod() <.B> LU
{ ///xx/weblogic60b2_win.exe 3)MM5 bb$
try{ 5OqsnL_V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); BL^Hj
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (']z\4o
SiteFileFetch fileFetch = new SiteFileFetch(bean); jJQfCOD$
fileFetch.start(); 9v3Nba
} `e;Sjf<
catch(Exception e){e.printStackTrace ();} CpdY)SMSL
5<8>G?Y
q9z!g/,d/
} zyn =Xv@p
B-p5;h>
K>JU/(
public static void main(String[] args) kT=|tQ@
{ 3A/MFQ#2
new TestMethod(); f!Nc+
} ;HwJw\fo
} T ]nR XW$
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