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)); qx18A
} 8+k\0fmy
for(int i=0;i<nEndPos.length-1;i++) !l?Go<^*L
{ (Q o
nEndPos = nStartPos[i+1]; [D[s^<RJs
} h1z[ElEeoP
nEndPos[nEndPos.length-1] = nFileLength; >DBaKLu\
} ]ctUl#j
} ]!d #2(
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'VS!<
//启动子线程 W#P)v{K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IiHl"2+/
for(int i=0;i<nStartPos.length;i++) beRpA;
{ B[Fx2r`0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R(74Px,/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >)=FS.?]
nStartPos,nEndPos,i); t4GG@`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i;s&;_0{
fileSplitterFetch.start(); [c+[t3dz
} "9!ln
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M`-#6,m3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X~*1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U; JZN
nEndPos = " + nFileLength); \U(qv(T
// fileSplitterFetch[nPos.length-1].start(); F-R4S^eV
1#qyD3K
D.kLx@Z
//等待子线程结束 Ck%nNy29
//int count = 0; 3 q^3znt
//是否结束while循环 ^ b{0|:
boolean breakWhile = false; J(ZYoJ
&p8b4y_
y))d[1E
while(!bStop) 0UB)FK,9
{ %"r3{Hs
write_nPos(); z4!TK ps
Utility.sleep(500); ?x7zYE,6
breakWhile = true; &W`."
gXZC%S
dT4?8:
for(int i=0;i<nStartPos.length;i++) '`p#%I@
{ x9bfH1
if(!fileSplitterFetch.bDownOver) T?4MFx#
{ $ jWe!]ASU
breakWhile = false; 2 DJs'"8
break; 7m~.V[l1
} y2;uG2IS_g
} yDg`9q.ckm
if(breakWhile) eU&[^
break; KC9_H>
%JeT,{
5MfbO3
//count++; 5,cq-`
//if(count>4) J.W0F#?
// siteStop(); X,y0J
} cK%Sty'8+
.|^L\L(!
i2j_=X-
System.err.println("文件下载结束！"); m^Qc9s#D
} -f@~{rK.L
catch(Exception e){e.printStackTrace ();} &\#If:
} I(y:Td
ShbW[*5
V]dzKNFi
//获得文件长度 Clr~:2g\
public long getFileSize() _LU]5$\b
{ =&jLwy
int nFileLength = -1; o *)>aw
try{ L}5nq@Uu)
URL url = new URL(siteInfoBean.getSSiteURL()); Z`y%#B6x.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y> ElE-
httpConnection.setRequestProperty("User-Agent","NetFox"); !LB#K?I
Opx"'HC@G
OPOL-2<wiy
int responseCode=httpConnection.getResponseCode(); |(G^3+5Uwm
if(responseCode>=400) HJWk%t<
{ .Y|5i^i9{
processErrorCode(responseCode); zO)A_s.6K
return -2; //-2 represent access is error n`gW&5,,z
} Mhp6,JL
3]"RaI4Q0
V<:scLm#OF
String sHeader; *;@V5[^3I?
+NWhvs
k|Mj|pqA
for(int i=1;;i++) z/Z 0cM#
{ qp$Td<'Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Qau\6p>^
//Utility.log(in.readLine()); 3pg_`
sHeader=httpConnection.getHeaderFieldKey(i); xc{$=>'G
if(sHeader!=null) m%au* 0p
{ LgFF+z
if(sHeader.equals("Content-Length")) qM%l
{ {WJ9!pA!lk
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); w6FtDl$
break; P(AcDG6K
} vdA3
} U?BuV
else =E$Hq4I
break; _voU^-
} 21ng94mC
} $bSnbU<
catch(IOException e){e.printStackTrace ();} &(&5ao)5
catch(Exception e){e.printStackTrace ();} o^HzE;L}
)vWI{Q]r
,xmL[Yk,
Utility.log(nFileLength); h2~b%|Pv
9?W!E_
/WqiGkHV*
return nFileLength; J;@g#h?
} Y6<"_
93I.Wp_{
>Z%qkU/
//保存下载信息（文件指针位置） .$&_fUY
private void write_nPos() )/uu~9SFd
{ v:.`~h/b
try{ U4PnQ K,
output = new DataOutputStream(new FileOutputStream(tmpFile)); -hv<8bC~4
output.writeInt(nStartPos.length); sUl/9VKl
for(int i=0;i<nStartPos.length;i++) 3jx5Lou)&
{ Z'/sZ3Q}
// output.writeLong(nPos); RC{|:@]8
output.writeLong(fileSplitterFetch.nStartPos); y*K]z
output.writeLong(fileSplitterFetch.nEndPos); .zDm{_'
} |Iq#Q3w
output.close(); 3"B$M
} oW7\T!f
catch(IOException e){e.printStackTrace ();} &4]~s:F
catch(Exception e){e.printStackTrace ();} lJ y\Ky(*
} A\xvzs.d
8<#S:O4kA
oY;=$8y<q
//读取保存的下载信息（文件指针位置） ?-.Qv1hs6p
private void read_nPos() $/Rr|<
{ L`"B;a&
try{ aJ;6!WFW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t^ax:6;"|
int nCount = input.readInt(); ZV,1IaO
nStartPos = new long[nCount]; %v)m&VUi%
nEndPos = new long[nCount]; Fke_ms=I^
for(int i=0;i<nStartPos.length;i++) vdS)EIt
{ y*6-?@
nStartPos = input.readLong(); *.g@6IkAQ
nEndPos = input.readLong(); %p wpRD@
} \9FWH}|
input.close(); Y\cQ"9
} 8y$c\Eu(mF
catch(IOException e){e.printStackTrace ();} HzuB.B<
catch(Exception e){e.printStackTrace ();} 83~9Xb=!\
} O\;R (
.LQvjK[N
@ckOLtxE>
private void processErrorCode(int nErrorCode) vJ`'x
{ 2p6`@8*34
System.err.println("Error Code : " + nErrorCode); Wa{()Cz
} @20~R/vh
&i/QFO7y}
cwK+{*ZH/
//停止文件下载 ;`p!/9il
public void siteStop() dF (m!P/R
{ Lc0yLm
bStop = true; xWhi>
for(int i=0;i<nStartPos.length;i++) a d,0*(</
fileSplitterFetch.splitterStop(); t93iU?Z
wfE%` 1
Z{#;my*X|
} PR{y84$
} 3jaY\(`%h
//负责部分文件的抓取 =5zx]N1r
**FileSplitterFetch.java 6X1_NbC
*/ ,sn/FT^; q
package NetFox; +[2X@J
OvFWX%uY
hp:8e@
import java.io.*; |izf|*e
import java.net.*; LEM^8G]O
ptcG:
;?-`n4B&
public class FileSplitterFetch extends Thread { VOmWRy"L
JE[+
1Vden.H*CI
String sURL; //File URL ]n/fB|tE
long nStartPos; //File Snippet Start Position l>H G|ol
long nEndPos; //File Snippet End Position 4t Z. T9d
int nThreadID; //Thread's ID Wd0$t
boolean bDownOver = false; //Downing is over #!h +K"wX
boolean bStop = false; //Stop identical [+j39d.Q
FileAccessI fileAccessI = null; //File Access interface pbM"tr_A{
s3., N|
L.]mC!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9F*],#ng
{ |ULwUi-r
this.sURL = sURL; 1zz.`.R2U
this.nStartPos = nStart; 1!;}#m7v
this.nEndPos = nEnd; #"Wh$x%
nThreadID = id; fUJ\W"qya
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pPezy:
} l}Fa-9_'
#9Fe,
OP-%t\sj>
public void run() JN{xh0*
{ _tGR:E
while(nStartPos < nEndPos && !bStop) N]p|c3D
{ <;?&<qMo,P
aD5G0d?u
N%2UL&w#B
try{ Ya_4[vR<
URL url = new URL(sURL); "eH~/6A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c/c%-=
httpConnection.setRequestProperty("User-Agent","NetFox"); te+5@k#t
String sProperty = "bytes="+nStartPos+"-"; CCX!>k]
httpConnection.setRequestProperty("RANGE",sProperty); a%wK[yVp
Utility.log(sProperty); {]a 6o[}u
h0N*hx
d\cwUXf J
InputStream input = httpConnection.getInputStream(); ,0~/ Cn
//logResponseHead(httpConnection); M~G1ZB
SwDUg}M~
`tCOe
byte[] b = new byte[1024]; ^1%gQ@P
int nRead; M?UlC
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p2=Sbb
{ 1qs~[7{C1
nStartPos += fileAccessI.write(b,0,nRead); UJ0Dy` f
//if(nThreadID == 1) Qbc62qFu!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L-ZJ[#D
} o6} +5
0shNwV1zF
wFW2m
Utility.log("Thread " + nThreadID + " is over!"); J)l]<##
bDownOver = true; `P`nqn
//nPos = fileAccessI.write (b,0,nRead); VH{SE7
} y %k`
catch(Exception e){e.printStackTrace ();} >e4
} {d;eZt `
} ,]N!I%SI
SZ9xj^"g
`;^%t
//打印回应的头信息 @UO=)PxN3
public void logResponseHead(HttpURLConnection con) Z{ntF
{ Cf_Ik
for(int i=1;;i++) PAe2hJ
{ zN\~v
String header=con.getHeaderFieldKey(i); C/P,W>8
if(header!=null) {C%/>e2-%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N_vVEIO9
Utility.log(header+" : "+con.getHeaderField(header)); 7eh|5e$@
else mf26AIlkQ
break; 5k`[a93T
} F_SkS?dB
} tVhY=X{N?
OpwZTy}1}
t[6g9e$
public void splitterStop() S?{|qlpy
{ Sa&~\!0t
bStop = true; ,i2%FW
} qj71 rj
Ru?Ue4W^b
Av*R(d=`
} .P=uR8
9?*BN\E5S
'aB0abr|
/* o} #nf$v(
**FileAccess.java S.+)">buH
*//文件访问(定位，写) V*l0|,9
package NetFox; 4/{Io &|
import java.io.*; ~'WvIA (
ufdC'2cp8
DA oOs}D
public class FileAccessI implements Serializable{ B{ NKDkDH
FhB^E$r%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Vgs( feGs
RandomAccessFile oSavedFile; JF*JFOb
long nPos; F9e$2J)C
W%09.bF
]lF'o&v]
public FileAccessI() throws IOException "F+ 9xf&r
{ Jkt L|u:k
this("",0); H^Xw<Z=
} DYH-5yX7
Z*kGWL
\n850PS
public FileAccessI(String sName,long nPos) throws IOException @A6\v+ih
{ n@BE*I<"
oSavedFile = new RandomAccessFile(sName,"rw"); +1p>:cih
this.nPos = nPos; 9`^VuC'
oSavedFile.seek(nPos); ?B %y)K
} -8tWc]c |4
zQ {g~x
nJ4h9`[>V
public synchronized int write(byte[] b,int nStart,int nLen) 4j!MjlG$
{ ?9i7+Y"
int n = -1; $B4}('&4FQ
try{ `QR2!W70o3
oSavedFile.write(b,nStart,nLen); N_L&!%s
n = nLen; Bh*~I_Ta>
} wCBL1[~C
catch(IOException e) UTUIL D
{ }se)=7d8 Z
e.printStackTrace (); dv%gmUUf}k
} ~GfcI:Zz&
<uL?7P
'oTcx Jx
return n; NV;5T3
} ywk;
Qd!;CoOmZs
,I=ClmR
} $X9Ban]
(k M\R|
Xr M[8a
/* KLqu[{y.'
**SiteInfoBean.java ;sNyN#
*/ iTD}gC
package NetFox; P1 (8foZA
> Q@*o
(eJr-xZ/
public class SiteInfoBean { $t1]w]}d
SlZL%C;
`+B+RQl}[
private String sSiteURL; //Site's URL 9;Wz;p
private String sFilePath; //Saved File's Path qB]z"Hfq,
private String sFileName; //Saved File's Name dWD,iO_"@
private int nSplitter; //Count of Splited Downloading File h1K 3A5
6FSw_[)
.2 UUU\/5
public SiteInfoBean() ~A8lvuw3
{//nSplitter的缺省值为5 vG\]xM'u
//default value of nSplitter is 5 w}NgFrL
this("","","",5); A i9*w?C
} K;6K!6J:[
tb/u@}")
FPMhHHM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4,s: G.g
{ 'cw0FpQ;
sSiteURL= sURL; ~uC4>+dk
sFilePath = sPath; /l+x&xYD
sFileName = sName; l,*Q?q
this.nSplitter = nSpiltter; H gNUr5p
< q;]
; tvB{s_
} /gy;~eB01
(:+IS W
h,140pW
public String getSSiteURL() 4C01=,6ye
{ -ZQ3^'f:0J
return sSiteURL; &%qD Som3
} )r?i^D&4
o,\%c"mC
V]k!]
public void setSSiteURL(String value) a2=wJhk
{ mu"]B]
sSiteURL = value; .j}u'!LKul
} A$XjzTR
nQ$N(2<Fe
U%k e5uwP
public String getSFilePath() mZ/B:)_
{ Z(as@gjH
return sFilePath; }lpcbm
} i;)g0}x`
0BaL!^>
j{U-=[$'
public void setSFilePath(String value) Go`omh b
{ o4~ft!>
sFilePath = value; oSa FmP
} 34;c00
lmmyDg1R
[7I|8
public String getSFileName() )&dhE^ O
{ d}l^yln
return sFileName; !+hX$_RT
} VpVw:Rh>
huKz["]z[
p*npY"}v
public void setSFileName(String value) 3gabk/
{ TJ;v}HSo
sFileName = value; \o % ES
} r`B+ KQ4
t91CxZQ^s
*|E@81s#
public int getNSplitter() [qZ4+xF,,
{ HqF8:z?v
return nSplitter; X!2|_
} oTa! F;I
8OFrW.>[
ZcWl{e4
public void setNSplitter(int nCount) Y}?@Pm drz
{ n/|/Womr
nSplitter = nCount; epG;=\f}m`
} R3@iN&
} =oh6;Ojt
XdS<51 C
~IqT>
/* njq-iU
**Utility.java X4k/7EA
*/ F_r eBPx
package NetFox; i@I%$!cB
ix#
KdR&OBm
public class Utility { <.v6w*+{/
n9J>yud|
[KE4wz+s{
public Utility() BuvBSLC~
{ u?J(l)gd
g8x8u|
\)#3S $L~
} &qpA<F@7
3+$O#>
//线程睡眠 )xK!i.
public static void sleep(int nSecond) n=>Gu9`
{ 785iY865
try{ r9t{/})A
Thread.sleep(nSecond); =|#-Rm^YB
} PA=BNKlH
catch(Exception e) *7vPU:Q[
{ 6,h<0j{
e.printStackTrace (); jF5JpyOc
} &%bX&;ECzf
} tQ|I$5jNJ
Y~:7l5C
//日志 kL3=7t^ 1
public static void log(String sMsg) .o8Gi*PEY
{ Sh*P^i.]+
System.err.println(sMsg); ^\6UTnS.
} TSk6Q'L\v
l )4OV>
Uy_=#&jg
public static void log(int sMsg) 2~4C5@SxL
{ P>kx{^
System.err.println(sMsg); 4HHf3j!5
} k^]~NP
} ;i:7E#@
' #mC4\<W8
lt4UNJ3w
/* BxqCV%9o
**TestMethod.java xV6j6k
*/ hf-S6PEsM
package NetFox; ,]Ma,2
dkLR Q
*,pqpD>
public class TestMethod { `Qhh{
k$2Y)
6GN'rVr!Z
public TestMethod() ;uDFd04w [
{ ///xx/weblogic60b2_win.exe +W1rm$Q
try{ k8JPu"R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9e5UTJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); PA/6l"-`3
SiteFileFetch fileFetch = new SiteFileFetch(bean); b1OB'P8
fileFetch.start(); DNy)\+[
} <f6Oj`{f4
catch(Exception e){e.printStackTrace ();} *Tlv'E.M
72 6y/o
8xX{y#
} 2P=;r:cx
HHYcFoJwYN
+x2xQ8#|~~
public static void main(String[] args) P:vy
{ O+N-x8W{
new TestMethod(); <gy'@w?
} 6>Cubb>
} t|m3b~Oyv
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