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)); Q @2(aR
} A/Khk2-:
for(int i=0;i<nEndPos.length-1;i++) wO"GtVd
{ =w<VT%
nEndPos = nStartPos[i+1]; fW~*6ln
} *?8RXer
nEndPos[nEndPos.length-1] = nFileLength; )&.!3y 660
} abZdGnc
} (5;D7zdA
/R%^rz'w
V:\]cGA{
//启动子线程 8Inx/>eOI
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0yHjrxc$
for(int i=0;i<nStartPos.length;i++) 5 R*lVUix
{ h#{T}[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 93I'cWN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 55hyV{L%
nStartPos,nEndPos,i); IT1PPm
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nC~fvyd<P
fileSplitterFetch.start(); } gkP
} b%nkIPA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ] C,1%(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6wpU6NU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b}%g}L D
nEndPos = " + nFileLength); >Me]m<$E;
// fileSplitterFetch[nPos.length-1].start(); B~_Spp
>Zdi5') 5
dYyW]nZ&
//等待子线程结束 ~Oh=
//int count = 0; {NeWdC
//是否结束while循环 l.7d$8'\
boolean breakWhile = false; IIaxgfhZ
5w-JPjH
zKJ.Tj W
while(!bStop) ih!~G5Xi9i
{ 4zzlazU
write_nPos(); E0`[G]*G
Utility.sleep(500); MW]8;`|jC
breakWhile = true; Xb+3Xn0}&8
(zmNa}-
{{E jMBg{
for(int i=0;i<nStartPos.length;i++) kr{)
{ M;qb7Mu
if(!fileSplitterFetch.bDownOver) x(vai1CrdH
{ tE:X,Lt[
breakWhile = false; vpafru4
break; WFj*nS^~l
} DoG%T(M!a9
} ,F}r@
if(breakWhile) P/`m3aSzX.
break; "!a`ygqpT
+@>:%yX
Tc,$TCF
//count++; }3sN+4
//if(count>4) gV.f*E1C
// siteStop(); 3"vRK5Bf
} &>V/X{>$`K
!3HsI|$<G
F8 ?uQP8
System.err.println("文件下载结束！"); (!ZV9S
} ?C~X@sq
catch(Exception e){e.printStackTrace ();} #|ddyCg2
} cdN/Qy
!Y|8z\Q
fPrb%
//获得文件长度 Ivjw<XP6K
public long getFileSize() IwM8#6;S~
{ _iq2([BpL
int nFileLength = -1; JE9>8+
try{ wlL8X7+:
URL url = new URL(siteInfoBean.getSSiteURL()); 0`Gai2\1@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R|H[lbw
httpConnection.setRequestProperty("User-Agent","NetFox"); = uk`pj[l
Me<du& T
\KNdZC?V2
int responseCode=httpConnection.getResponseCode(); r!~(R+,c
if(responseCode>=400) rV~T>x
{ `11#J;[@G
processErrorCode(responseCode); wH#-mu#Yl<
return -2; //-2 represent access is error Tr$i= M
} g#Mv&tU
jPpRsw>
eB7>t@ED
String sHeader; & L3UlL
t5n2eOy~T
[5!'ykZ
for(int i=1;;i++) Kny%QBoiw
{ fZ{&dslg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <g*.p@o
//Utility.log(in.readLine()); 6I5o2i
sHeader=httpConnection.getHeaderFieldKey(i); OFIMi^@
if(sHeader!=null) %Dra7B%
{ n3*UgNg%fK
if(sHeader.equals("Content-Length")) ;n` $+g:>
{ pY,O_ t$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?-d Ain1w
break; e"PMvQ
} srsK:%`
} @7)Z
else u2\+?`Ox
break; :4{Qh
} v8>!Gft
} o|0 '0P
catch(IOException e){e.printStackTrace ();} VkWO}
catch(Exception e){e.printStackTrace ();} ]u;GNz}?
90?,-6
V8\$`NEP
Utility.log(nFileLength); tnN'V
(lieiye^
mZ~mf->%
return nFileLength; 2|$lk8/,
} )>?! xx_`
-`Da`ml
A"0wvk)UcY
//保存下载信息（文件指针位置） J &{qppN
private void write_nPos() _IC,9bbg
{ 'xQna+%h
try{ @T5YsX]qb7
output = new DataOutputStream(new FileOutputStream(tmpFile)); sE-x"c
output.writeInt(nStartPos.length); xcw%RUC-
for(int i=0;i<nStartPos.length;i++) 9^(HXH_f
{ Y:rJK|m
// output.writeLong(nPos); NoJUx['6
output.writeLong(fileSplitterFetch.nStartPos); I Jqv w
output.writeLong(fileSplitterFetch.nEndPos); 692Rw}/
} P$6W`^DZ
output.close(); 2rF?Q?$,B
} 4|FRg
catch(IOException e){e.printStackTrace ();} NP$e-" 1
catch(Exception e){e.printStackTrace ();} *&(2`#C;
} @X K>
1 pa*T!
nG!&u1*
//读取保存的下载信息（文件指针位置） KlY,NSlQ
private void read_nPos() #NWZk.S
{ O>nK,.
try{ ZGA)r0] P`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); FwXKRZa
int nCount = input.readInt(); T!Xm")d
nStartPos = new long[nCount]; 1]_?$)$T
nEndPos = new long[nCount]; <"hb#Tn
for(int i=0;i<nStartPos.length;i++) <V7SSm
{ j.<:00<
nStartPos = input.readLong(); MRjH40"2
nEndPos = input.readLong(); +{5JDyh0
} 1XqIPiXJ
input.close(); A<mj8qz
} o`b$^hv{A
catch(IOException e){e.printStackTrace ();} 1d/NZJ9
catch(Exception e){e.printStackTrace ();} Po'-z<}wS
} +ylxezc
xOwNCh
tCuN?_UG
private void processErrorCode(int nErrorCode) 3w t:5 Im
{ umZlIH[7
System.err.println("Error Code : " + nErrorCode); P4hZB_.=
} di"C]" ;
Tld1P69(
P{"WlJ
//停止文件下载 0[V&8\S~'T
public void siteStop() &7$,<9.
{ D/gd
bStop = true; kuWK/6l4
for(int i=0;i<nStartPos.length;i++) IRlN++I!
fileSplitterFetch.splitterStop(); 6e-#XCR{
FYp|oD2=1
gsLr=
} jK\V|5k
} "}0)YRz%
//负责部分文件的抓取 +R2^* *<
**FileSplitterFetch.java a];BW)
*/ cSY2#u|v
package NetFox; F9Ifw><XM
mGt\7&`
[u/zrpTk
import java.io.*; kyy0&L
import java.net.*; }l,T~Pjb
}5fU7&jA;3
0|.7Kz^
public class FileSplitterFetch extends Thread { 6W)xj6<@
*eHA: A_I
J ZVr&KZN
String sURL; //File URL U(rr vNt:t
long nStartPos; //File Snippet Start Position Ix*BI9E
long nEndPos; //File Snippet End Position -@YVe:$%b
int nThreadID; //Thread's ID V<7R_}^_7
boolean bDownOver = false; //Downing is over zj~8>QnKk
boolean bStop = false; //Stop identical Zx}NFcn
FileAccessI fileAccessI = null; //File Access interface Gojl0?
x?%rx}h
:hC {5!|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v9Z lNA7m!
{ 1 ;_{US5FR
this.sURL = sURL; g,00'z_D
this.nStartPos = nStart; B`g<Ge~
this.nEndPos = nEnd; Q mb[ e>
nThreadID = id; Rf)'HT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 S1D9AcK
} DCEvr"(
T)b3N|ONB
iifc;62
public void run() a"`g"ZRx
{ ) 1lJ<g#
while(nStartPos < nEndPos && !bStop) /W"Bf
{ s5c! ^,L8
(Wm/$P;
d%}crM-KTL
try{ r4;5b s6wm
URL url = new URL(sURL); ^m6k@VM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gl?P.BCW.&
httpConnection.setRequestProperty("User-Agent","NetFox"); k)H[XpM
String sProperty = "bytes="+nStartPos+"-"; v+xgxQGYH
httpConnection.setRequestProperty("RANGE",sProperty); anHBySI3
Utility.log(sProperty); hKk\Y{wv'
*23m-
1_Dn?G^H
InputStream input = httpConnection.getInputStream(); 7sQ]w
//logResponseHead(httpConnection); /Nj:!! AN
S[W9G)KWp
LP5eFl`|T
byte[] b = new byte[1024]; S1}1"y/
int nRead; qPFG+~\c
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5?V?
{ lH#@^i|G
nStartPos += fileAccessI.write(b,0,nRead); 5;3c<
//if(nThreadID == 1) "/4s8.dw+u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3e!3.$4M
} Nw9-pQ
|@o]X?^
6Nfof
Utility.log("Thread " + nThreadID + " is over!"); rK(x4]I l"
bDownOver = true; 8w{#R{w
//nPos = fileAccessI.write (b,0,nRead); d8Q_6(Ar|
} XBfiaj
catch(Exception e){e.printStackTrace ();} ,W)IVc
} q|47;bK'
} z;fd#N:
l}2%?d
%\(y8QV
//打印回应的头信息 {Y3_I\H8{
public void logResponseHead(HttpURLConnection con) veYsctK~
{ % +kT
for(int i=1;;i++) 37:b D
{ .LXh]I*
String header=con.getHeaderFieldKey(i); %{N$1ht^
if(header!=null) ch5`fm
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H6%!v1 u
Utility.log(header+" : "+con.getHeaderField(header)); R,d70w (_
else %=NM_5a}]
break; ooLnJY#
} `}k&HRn
} #a7Amh\nT
}#\;np
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public void splitterStop() v@$evmA
{ b*'=W"%\
bStop = true; !LHzY(
} zCBtD_@
y~]IVl"
C>w9 {h
} 1K? & J2
!^>LOH>j
LH3N}J({
/* }%o+1 <=
**FileAccess.java c:?#zX
*//文件访问(定位，写) %vf2||a$BS
package NetFox; v GR \GFm
import java.io.*; 6mI_Q2
wZ]BY;
RB lOTQjv
public class FileAccessI implements Serializable{ 5I8FD".i
[x$eF~Kp
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -CU7u=*b
RandomAccessFile oSavedFile; A]tf>H#1
long nPos; eZR8<Z%
>?G|Yz*kEJ
F653[[eQ
public FileAccessI() throws IOException N#pl mPrZ
{ PxP?hk
this("",0); rx}ujjx
} N1s$3Ul
\4\\575zp'
c5B_WqjJ
public FileAccessI(String sName,long nPos) throws IOException gq/ePSa
{ ,IT)zCpaBP
oSavedFile = new RandomAccessFile(sName,"rw"); #U!(I#^3
this.nPos = nPos; Kbz7
oSavedFile.seek(nPos); @ V7ooo!
} Z5*(W;;
}GoOE=rhY
P[#WHbn
public synchronized int write(byte[] b,int nStart,int nLen) qOcG|UgF
{ aV?}+Y{#
int n = -1; skR,M=F~
try{ 9aF..
oSavedFile.write(b,nStart,nLen); :bM$;
n = nLen; /v bO/Mr
} RXx?/\~yd;
catch(IOException e) qa0JQ_?o]
{ F)E7(Un`8
e.printStackTrace (); 0'q(XB`i=
} H%01&u
vHI"C %
Z+``/Q]>+
return n; FQ9csUjpB
} NqQ(X'W7
Hz3 S^o7
$@u^Jt, ?
} PFDWC3<
t5X^(@q4N
CJ}@R.Zy
/* /4"S}P>f
**SiteInfoBean.java xPfnyAo?%z
*/ O&?CoA?
package NetFox; \6`%NhkM_
?2<6#>(7a
F;MT4*4
public class SiteInfoBean { <_sT]?N#
cP#]n)<
8Snq75Q<
private String sSiteURL; //Site's URL )HzITsFZKT
private String sFilePath; //Saved File's Path ek{PA!9Sk
private String sFileName; //Saved File's Name 2,XqslB)
private int nSplitter; //Count of Splited Downloading File ]:E! i^C`Z
?CUp&L0-"
:S+U}Sm[
public SiteInfoBean() ?^yh5
{//nSplitter的缺省值为5 uu@'02G8
//default value of nSplitter is 5 G8(i).Q
this("","","",5); dWB8
} !(ux.T0
>Dp6@%
X^ ^?}>t[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1&@wb'MBs.
{ "mP*}VF
sSiteURL= sURL; p=`x
sFilePath = sPath; hml\^I8Q>F
sFileName = sName; i3kI2\bd/
this.nSplitter = nSpiltter; #Rm=Em}d
L$TKO,T
p\]LEP\z,
} DO-K
Ji}IV
(y+5d00
public String getSSiteURL() li_pM!dWU_
{ [>J~M!yu:r
return sSiteURL; {ZsWZJ!
} 8F\Msx
Acq>M^E3
^0ZKHR(}e
public void setSSiteURL(String value) j=jrzG+`
{ E'BH7JV
sSiteURL = value; _@~kYz
} FUqhSW
<C.$Db&9
RkH oT^
public String getSFilePath() f\F_?s)_y
{ ?9r,Y;,H
return sFilePath; G}dOx}kT
} Lq $4.l[j
2W:?#h3
}b]y 0"
public void setSFilePath(String value) kJ<Xq
{ f/[?5M[
sFilePath = value; 8apKp?~yW
} Uo[5V|>X6
hzPB~obC
v!RB(T3
public String getSFileName() .McoW7|Y
{ l6DIsR
return sFileName; *6x^w%=A
} ZLio8
;pNbKf:
]I' xLh`
public void setSFileName(String value) cA*X$j6
{ q(PT'z
sFileName = value; >A(?Pn{|a
} dZiWVa
u*-<5&X
;!Z7-OZX
public int getNSplitter() o`1V
{ CT:eV7<>s
return nSplitter; m6Cd^'J9^
} E~@HC5.M
l0_E9qh-i
U;Y}2
public void setNSplitter(int nCount) >5vl{{,$K
{ er7/BE&
nSplitter = nCount; 09;'z
} tG^?fc
} ]-Y]Q%A4
FQ~ead36C
iN/!k.ybW}
/* [BR}4(7
**Utility.java RJsG]`
*/ f, j(uP
package NetFox; u-M$45vct
)E~\H+FP6
;3?J#e6;
public class Utility { "JLhOTPaHf
W;g+R-
5<BV\'
public Utility() E4aCGg
{ f{5|}PL
SU}oKii /
V #\ZS{'J
} iGeT^!N
W!0
//线程睡眠 bOIM0<(h
public static void sleep(int nSecond) ,Yprk%JT
{ Eno2<<
try{ CU^3L|f2N
Thread.sleep(nSecond); @C [|'[xQ
} ,~?A. 5
catch(Exception e) \C2P{q/m
{ {,C8}8a W
e.printStackTrace (); %ih7Jt
} #`)-$vUv^f
} hRZS6" #
-%gd')@SfD
//日志 nC{rs+P
public static void log(String sMsg) /z?7ic0
{ M"l rwun^
System.err.println(sMsg); oUKbzr/C
} F`V[G(f+r
qg:I+"u
4e\`zy
public static void log(int sMsg) Fl3r!a!P,
{ d47:2Zj
System.err.println(sMsg); '2J6%Gg
} QV7c9)<]'}
} o@`E.4
_@;3$eB
'{k Nbx51
/* YeVc,B'
**TestMethod.java ~ 2oP,
*/ :ItW|
package NetFox; 2bxMIr
H;Qn?^
q]%bd[zkz
public class TestMethod { QuRg(K%:
^(JbJ@m/
Fj('l
public TestMethod() jz7ltoP
{ ///xx/weblogic60b2_win.exe <Jrb"H[T"
try{ u#,'ys
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w:xKgng=L
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +4nR&1z$
SiteFileFetch fileFetch = new SiteFileFetch(bean); .EZ{d
fileFetch.start(); D#[ :NXahn
} (E(:F[.S
catch(Exception e){e.printStackTrace ();} j/mp.'P1k
FY}*Z=D%
yB{o_1tc
} tskODM0Zf
&b")`p&K
B(Q.a&w45t
public static void main(String[] args) ]3u'Qv}o
{ !!O{ ppM
new TestMethod(); UKQ&TV}0
} 2.2a2.I1
} 3C[4!>|
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