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)); |]^! 4[!U
} \}c50}#0
for(int i=0;i<nEndPos.length-1;i++) lsf?R'1
{ eu/Sp3@v
nEndPos = nStartPos[i+1]; s47"JKf"
} ywBo9|%T
nEndPos[nEndPos.length-1] = nFileLength; l;i u`
} breVTY7 S
} DSa92:M}
Z0^do
>eI(M $
//启动子线程 epe}^Pl
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q4 S8NqE
for(int i=0;i<nStartPos.length;i++) +[qy HTcG
{ #{PNdINoU
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /pEkig7M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $80/ub:R
nStartPos,nEndPos,i); Wb$bCR#?<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HRh".!lxy
fileSplitterFetch.start(); o$;x[US
} 6jA Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4Yk(ldR~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OC.@C}u
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M1\/ueOe
nEndPos = " + nFileLength); 0}!lN{m?
// fileSplitterFetch[nPos.length-1].start(); *?\Nioii
<#Dc(VhT
ppS`zqq $
//等待子线程结束 J(GLPCO$K
//int count = 0; l1-FL-1
//是否结束while循环 MR: {Ps&,
boolean breakWhile = false; C5?M/xj
Nq3P?I(<
6=D;K.!
while(!bStop) 3._fbAN%e
{ DO; 2)ZQ%
write_nPos(); L"0L_G
Utility.sleep(500); Fh;(1X75I
breakWhile = true; '-_PO|}
,y @3'~
eA_4,"{
for(int i=0;i<nStartPos.length;i++) 4v7RX
{ ujedvw;sO
if(!fileSplitterFetch.bDownOver) ^}#!?"Y
{ KYaf7qy]
breakWhile = false; D=$<Ex^p
break; ^TGHWCK!t
} lw{|~m5`
} c+c^F/
if(breakWhile) Uyh#g^r
break; VdgPb (
7BnP,Nd"W
P^ VNB
//count++; b6ddXM\Z
//if(count>4) 9#7zjrB
// siteStop(); ~gD'up@$/
} V8/o@I{U[
nEYJ?_55
[z9i v~
System.err.println("文件下载结束！"); |SmN.*&(9
} U;/ )V
catch(Exception e){e.printStackTrace ();} @AFLFX]
} J^T66}r[f,
ub&1L_K
L $~Id
//获得文件长度 `y(3:##p
public long getFileSize() n1|%xQBU@
{ kW9STN
int nFileLength = -1; bYfcn]N
try{ B(5g&+{Lq~
URL url = new URL(siteInfoBean.getSSiteURL()); 4$rO,W/&0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =/;(qy9.-R
httpConnection.setRequestProperty("User-Agent","NetFox"); Q\Eq(2p
@{G(.S
SzDi=lY
int responseCode=httpConnection.getResponseCode(); *SZ<ori
if(responseCode>=400) J.*=7zmw
{ *4bV8T>0Z
processErrorCode(responseCode); 7pNh|#Uv'
return -2; //-2 represent access is error C*$/J\6xy
} >4c 1VEi
4^r}&9C~
ME.LS2'n
String sHeader; }z[se)s
Ic*Q(X
sq%f%?(V
for(int i=1;;i++) 0IZV4{
{ vzU%5,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !Kis,e
//Utility.log(in.readLine()); DbDpdC;
sHeader=httpConnection.getHeaderFieldKey(i); /i<g>*82
if(sHeader!=null) [3s~Z8 pP
{ nz(OHh!}u
if(sHeader.equals("Content-Length")) `'/8ifKz
{ Z-p_hNb
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \Z$*8z=
break; n~h%K7 c
} @AwH?7(b
} |7argk+
else j'W)Nyw$[
break; rr*IIG&.5
} E4{8 $:q=
} \,WPFV
catch(IOException e){e.printStackTrace ();} GM5::M]fS
catch(Exception e){e.printStackTrace ();} mxIEg?r(
m{g{"=}YR
yC -4wn*
Utility.log(nFileLength); C-Mop,w
xc!"?&\*
\<5xf<{
return nFileLength; o{qbbJBC
} B`vV[w?
tNjrd}8s
1@am'#<
//保存下载信息（文件指针位置） ~HELMS~-
private void write_nPos() m4EkL
{ ~[C m#c
try{ ^^v!..V]J
output = new DataOutputStream(new FileOutputStream(tmpFile)); .hvIq .vr
output.writeInt(nStartPos.length); >7n(*M
for(int i=0;i<nStartPos.length;i++) vXc<#X9
{ /q=<OEC
// output.writeLong(nPos); ^71sIf;+
output.writeLong(fileSplitterFetch.nStartPos); qU"+0t4
output.writeLong(fileSplitterFetch.nEndPos); d-Sm<XHu.
} j8lbn|.
output.close(); js{ RaR=
} ]!/1qF
catch(IOException e){e.printStackTrace ();} (qaY,>je]D
catch(Exception e){e.printStackTrace ();} wm}i+ApK
} A >e%rx
H*Yyo?
<_D+'[
//读取保存的下载信息（文件指针位置） j,~h:MT
private void read_nPos() %l>^q`p
{ D~-Ri`k.
try{ P63f0F-G
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O@l`D`
int nCount = input.readInt(); Z@1rs#
nStartPos = new long[nCount]; 3+)i23[4=\
nEndPos = new long[nCount]; z=!xN5
for(int i=0;i<nStartPos.length;i++) [j5L}e!T
{ Uu G;z5
nStartPos = input.readLong(); N(D_*% 96
nEndPos = input.readLong(); G,J$lTX
} @Fo0uy\G
input.close(); o/Z?/alt4
} O%)w!0
catch(IOException e){e.printStackTrace ();} 6JJ%`Uojh
catch(Exception e){e.printStackTrace ();} SW bwD/SN
} ]86U-`p
Ef#%4ky
C\1Dy5
private void processErrorCode(int nErrorCode) =!Ok079{[
{ U5" C"+ 3
System.err.println("Error Code : " + nErrorCode); / JlUqC
} I(C_}I>Wb
LNe-]3wB
!dZC-U~
//停止文件下载 N/Z<v* i"
public void siteStop() 4B) prQ3
{ !bQ5CB
bStop = true; zE<}_nA
for(int i=0;i<nStartPos.length;i++) MgA6/k
fileSplitterFetch.splitterStop(); GR/ p%Y(
90Q}9T\
O4 [[9
} 9Czc$fSSt
} Ur_~yX]Mo
//负责部分文件的抓取 m+CvU?)gJ
**FileSplitterFetch.java [N{Rd[{QTL
*/ z55P~p
package NetFox; H1+G:TM
sq*sbdE
pm^[ve
import java.io.*; NKO5c?ds
import java.net.*; k5|h8%h8
] OR]
A07FjT5w8
public class FileSplitterFetch extends Thread { 9"&HxyOfX
z[l17+v
;+cZS=
String sURL; //File URL w J; y4
long nStartPos; //File Snippet Start Position kZfO`BVL
long nEndPos; //File Snippet End Position <wa}A!fu
int nThreadID; //Thread's ID iB{O"l@w
boolean bDownOver = false; //Downing is over i,,UD
boolean bStop = false; //Stop identical ^IY1^x
FileAccessI fileAccessI = null; //File Access interface \=1k29O
=Bl#CE)X
H~fZA)W 4Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $kg!XT{V
{ O]`CSTv'_
this.sURL = sURL; j$BM$q/c
this.nStartPos = nStart; F?3a22Zg#
this.nEndPos = nEnd; #TRPq>XzD
nThreadID = id; s<tdn[d
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yo3'\I
} FK0nQ{uB"
RaKL KZn
ob-y {x,R
public void run() Q@nxGm
{ 1jO/"d.8n
while(nStartPos < nEndPos && !bStop) Za5*HCo
{ Gw$U0HA[,
o^biO!4,
0fwo8NgX
try{ T-uI CMEf
URL url = new URL(sURL); 5_#wOz0u$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y ~xcJH
httpConnection.setRequestProperty("User-Agent","NetFox"); c=h{^![$
String sProperty = "bytes="+nStartPos+"-"; %\2 ll=p1
httpConnection.setRequestProperty("RANGE",sProperty); Z#%4QIz?
Utility.log(sProperty); zN0^FXGD
Y}Y2Vx
7C F-?M!
InputStream input = httpConnection.getInputStream(); ?FxxH*>"
//logResponseHead(httpConnection); M5CFW >T
(ybKACx
5l}v
byte[] b = new byte[1024]; PohG y
int nRead; ?=$a6o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,_D`0B6o
{ %TP0i#J
nStartPos += fileAccessI.write(b,0,nRead); <T,vIXwu+
//if(nThreadID == 1) kO+Y5z6=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8 W79
} zvL;.U
]`b/_LJN$F
M1-n
Utility.log("Thread " + nThreadID + " is over!"); r1}YN<+,s
bDownOver = true; W^Wr
//nPos = fileAccessI.write (b,0,nRead); =bi:<%"
} g kT`C
catch(Exception e){e.printStackTrace ();} cR*D)'/tl
} ~K5eO-
} X3P~z8_
Vr+X!DeY
_Y?p =;
//打印回应的头信息 Ys|tGU
public void logResponseHead(HttpURLConnection con) .i) H1sD
{ KY~p>Jmh
for(int i=1;;i++) bx#GOK-
{ qH1[BsOx
String header=con.getHeaderFieldKey(i); 4$oNh)+/h
if(header!=null) 40w,:$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N7v7b<6
Utility.log(header+" : "+con.getHeaderField(header)); .y\j .p
else HZX(kYV
break; Kc$j<MRtv
} kj{z;5-dl
} J^m#984
E_[|ZrIO&*
~oWCTj-
public void splitterStop() U-&dn%Sq
{ |3<tDq@+
bStop = true; W<_9*{|E;
} R*|y:T,H
q$L=G
>x]b"@Hkw
} CoO..
gi\2bzWkbX
hd0d gc
/* 4jbqV
**FileAccess.java <=[,_P6|
*//文件访问(定位，写) FrT.<3
package NetFox; 7Ko<,Kp2b
import java.io.*; O9?t,1
A/ZZ[B-
WT;4J<O/
public class FileAccessI implements Serializable{ E%8Op{zv_
v'na{"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $a.fQ<,\X
RandomAccessFile oSavedFile; k<(G)7'gm
long nPos; #;~`+[y?\
?-C=_eZJ
g?&_5)&
public FileAccessI() throws IOException RdaAS{>Sk
{ Jmg<mjq/G
this("",0); Gmi ^2?Z(
} R!{^qHb
jeLRS8];
E}6q;"[
public FileAccessI(String sName,long nPos) throws IOException H2[VZ&Pg
{ 7~&
oSavedFile = new RandomAccessFile(sName,"rw"); r*_z<^d
this.nPos = nPos; !8YZ;l
oSavedFile.seek(nPos); k@:M#?(F
} Bu_/yKW
t7#lRp&
M:TN^ rA|
public synchronized int write(byte[] b,int nStart,int nLen) 0>{&8:
{ rG[iEY
int n = -1; m-T@Og
try{ >2vUFq`H
oSavedFile.write(b,nStart,nLen); QiO4fS'~W
n = nLen; r:N =?X`N
} LL% Aw)Q`
catch(IOException e) 1'Sr0 oEd3
{ ZW+M<G
e.printStackTrace (); {o>51fXc)
} b^s978qn#
>I*)0tE
={g.Fn(_
return n; t"# .I?S0
} &k53*Wo
Bk)E]Fk|
}SD*@w
} }Br=eaY
hSkI]%
k|uW~I)
/* 80m<OW1
**SiteInfoBean.java ;[nomxu|?
*/ vNWCv
package NetFox; +|0f7RB+R
IkWV|E
oyw*Z_9~
public class SiteInfoBean { a%nksuP3
n1XJuc~
4C:-1gu7
private String sSiteURL; //Site's URL LK>AC9ak<
private String sFilePath; //Saved File's Path ?58,Ja
private String sFileName; //Saved File's Name )\aCeY8o
private int nSplitter; //Count of Splited Downloading File !m {d6C[
1Jm'9iy3
E^s<5BC;
public SiteInfoBean() ~W/|RP7S
{//nSplitter的缺省值为5 OKo)p`BX
//default value of nSplitter is 5 QH>e_
this("","","",5); #!.26RM:P
} wqnrN6$jf
DjLSl,Z
xVnk]:c
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )t#>fnN
{ ]`+J!G,
sSiteURL= sURL; U3t$h
sFilePath = sPath; Z:(Zy
sFileName = sName; ]&b>P ;j:
this.nSplitter = nSpiltter; hnYL<<AA
r'F)8%
/`kM0=MMa
} OK]_.v}
rbt/b0ET
DYf3>xh>xb
public String getSSiteURL() HpKF7oJ'N
{ 7jS`4,
return sSiteURL; HuI?kLfj\
} n9H4~[JiC
ITssBB9
w. c]
public void setSSiteURL(String value) 2%Mgg,/~
{ $-w&<U$E
sSiteURL = value; "7z1V{ ;Y
} /_(q7:<ZF
e)M)q!nG
TC* 78;r
public String getSFilePath() mVsghDESJ)
{ ` W}Bc
return sFilePath; OF1fS\P<>
} QKHAN{hJ
1F,>siuh ,
FW@(MIH
public void setSFilePath(String value) zn)Kl%N^
{ "?HDv WP=w
sFilePath = value; "3;b,<0
} 'eYM;\%('
bXNM.K
,9.-A-Yw
public String getSFileName() }7HR<%<7
{ qdNt2SO
return sFileName; ISDeLUihY
} +1pY^#A
5H^"
rtn.^HF
public void setSFileName(String value) &;2@*#,
{ I.>SC
sFileName = value; 5Tg[-tl
} ozOvpi:k3%
O<>cuW(l
&_dM2lj{
public int getNSplitter() #I9hKS{
{ ""W*) rR
return nSplitter; 1yd}F`{8UF
} *l.tsICmbP
@,Kl"i;
|*5HNP
public void setNSplitter(int nCount) efrVF5,y?
{ xT8pwTO
nSplitter = nCount; (x!Tb2mlk
} ;r3Xh)k;
} <$@*'i^7Ez
YIn H8Ex
vPce6 Cl*
/* kn9e7OO##
**Utility.java Yc3Rq4I'G
*/ Wz+7CRpeP
package NetFox; _%gu<Ys
EQ%,IK/
De`p@`+<#~
public class Utility { 5H79-QLd
cVf}8qf)
n\w2e_g;N
public Utility() YwaWhBCIF
{ ^W%#Elf)
PBOZ^%k
xe@11/F
} Vo`,|3^
8Cef ]@x
//线程睡眠 rE?Fp
public static void sleep(int nSecond) ]L/AW
{ krMO<(x+
try{ Ba#wW E
Thread.sleep(nSecond); chakp!S=
} ~5]%+G
catch(Exception e) <,+nS%a
{ &xLCq&j1
e.printStackTrace (); Op5S'
} ?2nF1>1
} x2h5,.K
}8eu 9~
//日志 {?RVw`g&f
public static void log(String sMsg) ;hb_jW-0W
{ U["-`:>jfp
System.err.println(sMsg); C8W4~~1S
} 9D[Jn}E:
/8Ru O
0BrAgv"3a_
public static void log(int sMsg) $_f"NE}
{ 3%L@=q
System.err.println(sMsg); ><wYk)0E
} O6"S=o&
} 6%a:^f]
@8eQ|.q]Q
*?3c2Jg=E
/* Ku`u%5<
**TestMethod.java $(fhO
*/ .K`EflN
package NetFox; u:w
Ohn?>qQ
d;hv_h
public class TestMethod { s2`Qh9R
H&SoVi_V
o2rL&
public TestMethod() S!8gy,7<J
{ ///xx/weblogic60b2_win.exe G$A=Tu~
try{ Sp/<%+2(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F[)5A5+:Y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b6UpE`\z
SiteFileFetch fileFetch = new SiteFileFetch(bean); YhQ%S}
fileFetch.start(); N;S1s0FN
} {1;R&
catch(Exception e){e.printStackTrace ();} p6X-P%s
!:wA\mAd
l05'/duuJ
} )skz_a}]8
BcxALRWE
"cz'|z`
public static void main(String[] args) n?:%>Os$
{ * zt?y
new TestMethod(); -?p4"[
} {Jc.49
} Om_-#S
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