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)); ?#5)TAW
} 2}{[J
for(int i=0;i<nEndPos.length-1;i++) }k1[Fc|
{ B^1jd!m
nEndPos = nStartPos[i+1]; _qit$#wK;
} { F0"U=
nEndPos[nEndPos.length-1] = nFileLength; 6{Bvl[mhI
} M~sP|Ha"+
} gi A(VUwI>
;?o"{mbb
[woxCfSA
//启动子线程 a`||ePb|W~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y9:o];/
for(int i=0;i<nStartPos.length;i++) fQU_A
{ a.<!>o<t:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '?|.#D#-c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [o'}R`5)
nStartPos,nEndPos,i); +w?1<Z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Tq6@ 1j6p
fileSplitterFetch.start(); HV3D$~gF
} wZ8LY;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `Q^Vm3h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k/xNqN(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (w'k\y
nEndPos = " + nFileLength); [s!cc:JR
// fileSplitterFetch[nPos.length-1].start(); )o_$AbPt
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}>Lz\.Z/+[
//等待子线程结束 ku5g`ho
//int count = 0; "%t !+E>nr
//是否结束while循环 g.EKdvY"%H
boolean breakWhile = false; 1 pzd
qr/N?,
\AR3DDm
while(!bStop) 6dCqS
{ iu,Bmf^oD
write_nPos(); 2wh{[Q2f
Utility.sleep(500); 5al44[
breakWhile = true; Ks7kaX
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-E!V;Tgc%U
for(int i=0;i<nStartPos.length;i++) h9{'w
{ `=foB-(zt
if(!fileSplitterFetch.bDownOver) |B*`%7{+
{ CV,[x[L#{
breakWhile = false; qoD M!~
break; j[1^#kE
} "2/VDB4!FG
} 1<9m^9_ro
if(breakWhile) -Kf'02
break; +%RXV~
`!T6#6h
|c>A3 P$=B
//count++; )6zwprH!
//if(count>4) HaamLu
// siteStop(); d3C*]|gQ
} QO~TuC
z//6yr
=mk7'A>l
System.err.println("文件下载结束！"); 3?(||h{
} `S7${0e
catch(Exception e){e.printStackTrace ();} ?+#E&F
} ?3i-wpzMp
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sXSZ#@u,WN
//获得文件长度 pKSVT
public long getFileSize() Ec]cCLB
{ <tTn$<b
int nFileLength = -1; xF{<-b
try{ j&?NE1D>I
URL url = new URL(siteInfoBean.getSSiteURL()); 86@@j*c(@k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )Nq$~aAm
httpConnection.setRequestProperty("User-Agent","NetFox"); yyHr. C
0?j+d8*
BT+ws@|[
int responseCode=httpConnection.getResponseCode(); 'x10\Q65[
if(responseCode>=400) \bb,gRfP
{ !$+J7\&7p
processErrorCode(responseCode); dDk<J;~jGJ
return -2; //-2 represent access is error Lp/]iZ@
} S,v9\wN.
NC2PW+(
*%cI,}%
String sHeader; Pz+8u&~p
A|@d4+
2S8/ lsB
for(int i=1;;i++) nmN6RGx
{ 'bg%9}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9W7H",wR
//Utility.log(in.readLine()); GRj{*zs
sHeader=httpConnection.getHeaderFieldKey(i); gGdZ}9
if(sHeader!=null) 'gE_xn7j
{ G";yqG
if(sHeader.equals("Content-Length")) _B|g)Rdv
{ #,qikKjt2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TO)wjF_
break; M|`%4vk>
} ]?Ru~N}
} *pvhkJ g(
else sM~|}|p
break; FUm-Fp
} y#Ch /Jg?|
} .x1EdfHed/
catch(IOException e){e.printStackTrace ();} >UuLSF}
catch(Exception e){e.printStackTrace ();} uBs[[9je(
~GS`@IU}
?P`]^#
Utility.log(nFileLength); te'<xfG
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e}}xZ%$4|
return nFileLength; -]PW\}w1
} +3t(kQ
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zYj8\iER
//保存下载信息（文件指针位置） Dx Vt
private void write_nPos() ;LH?Qu;e
{ 4F8`5)RM
try{ c:~o e
output = new DataOutputStream(new FileOutputStream(tmpFile)); \aT._'=M+
output.writeInt(nStartPos.length); /)y~%0
for(int i=0;i<nStartPos.length;i++) /{1xpR
{ '&T4ryq3"
// output.writeLong(nPos); lTdYPqMi
output.writeLong(fileSplitterFetch.nStartPos); ">voi$Kzey
output.writeLong(fileSplitterFetch.nEndPos); oc-7gz)
} hgKs[ySo,3
output.close(); JCaT^KLz
} "Rs^0iT7>
catch(IOException e){e.printStackTrace ();} P67r+P,
catch(Exception e){e.printStackTrace ();} !Nl"y'B|
} Q.6pmaXrb
Ctt{j'-[
?^IM2}(p
//读取保存的下载信息（文件指针位置） g[@]OsX
private void read_nPos() hlkf|H
{ E9226
try{ I[<C)IG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 35jP</
int nCount = input.readInt(); sOLo[5y'
nStartPos = new long[nCount]; R`>E_SY
nEndPos = new long[nCount]; [N#2uo
for(int i=0;i<nStartPos.length;i++) kRE^G*?
{ UXa3>q>
nStartPos = input.readLong(); 94|BSxc
nEndPos = input.readLong(); n&[U/`o
} I%*o7"
input.close(); +5);"71
} iAWPE`u4
catch(IOException e){e.printStackTrace ();} ~"}-cl,
catch(Exception e){e.printStackTrace ();} {v]A`u)
} rmR7^Ycv/
a50{gb#
=`vUWONn
private void processErrorCode(int nErrorCode) &sWqSS
{ Fv5@-&y$W
System.err.println("Error Code : " + nErrorCode); XF{}St~(
} UO<%|{W+
='OPU5(;O
a*S4rq@
//停止文件下载 R[Kyq|UyVr
public void siteStop() KH2a 2
{ ^i#q{@g
bStop = true; cD2}EqZ 9
for(int i=0;i<nStartPos.length;i++) o $p*C
fileSplitterFetch.splitterStop(); 0xC{Lf&
b^5rV5d
MWsBZJRr
} 7ktf =Y
} /_woCLwQ#
//负责部分文件的抓取 v*l1"0$
**FileSplitterFetch.java o& $Fc8bH
*/ 0ltq~K
package NetFox; ?OvtR:hC
X )g<F
M_UhFY='
import java.io.*; OES+BXGX
import java.net.*; i>q]U:U
0P\)L`cG
{o5E#<)
public class FileSplitterFetch extends Thread { Ck(D: % ~s
!lL21C6g+
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String sURL; //File URL -5d8j<,
long nStartPos; //File Snippet Start Position d^WVWk K
long nEndPos; //File Snippet End Position zn>*^h0B
int nThreadID; //Thread's ID Ry[VEn>C1
boolean bDownOver = false; //Downing is over x@Z?DS$)
boolean bStop = false; //Stop identical =f{V<i~q
FileAccessI fileAccessI = null; //File Access interface f(7/
!}Cd_tj6
t#}/VnSQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &d9tR\}
{ p^7ZFUP
this.sURL = sURL; GZ UDI#
this.nStartPos = nStart; +;pdG[N
this.nEndPos = nEnd; x(5>f9bb
nThreadID = id; UFm E`|le
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~%k<N/B
} VGA?B@
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"+r8izB
public void run() 7oh6G
{ ]6W#P7
while(nStartPos < nEndPos && !bStop) B.;/N220P
{ -`FTWH
>j_,3{eJ
TR5"K{WDx
try{ :_i1)4[!
URL url = new URL(sURL); j!qO[CJJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^'*9,.ltd
httpConnection.setRequestProperty("User-Agent","NetFox"); 70mQ{YNN
String sProperty = "bytes="+nStartPos+"-"; S;a{wYF6v
httpConnection.setRequestProperty("RANGE",sProperty); \O^b|0zc
Utility.log(sProperty); D%Hz'G0|
u==bLl=$
;:hyW,J
InputStream input = httpConnection.getInputStream(); +JB. EW/
//logResponseHead(httpConnection); 2YdMsu~
j{0_K+B
3 =KfNz_
byte[] b = new byte[1024]; q[] "`?
int nRead; $j)Er.!9|R
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %f#3;tpC8
{ a7)q^;:O
nStartPos += fileAccessI.write(b,0,nRead); kNMhMEez
//if(nThreadID == 1) Se%FqI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j^"Z^TEBT
} mBhG"0:
qi.|oL9p
;mu9;ixZ
Utility.log("Thread " + nThreadID + " is over!"); cx&jnF#$
bDownOver = true; Gyw@+(l
//nPos = fileAccessI.write (b,0,nRead); `QC{}Oo^
} n1a;vE{!
catch(Exception e){e.printStackTrace ();} ~*ZB2
} L8Z[Ly+_
} 8tK8|t5+
L/1?PM
h3h2 KqM'
//打印回应的头信息 Ma0_!|i
public void logResponseHead(HttpURLConnection con) 'bN\bbR
{ l=`)yc.
for(int i=1;;i++) ;l[/<J
{ pj6Q0h)
String header=con.getHeaderFieldKey(i); Ge8&_7
if(header!=null) t IdH?x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0e^j:~*
Utility.log(header+" : "+con.getHeaderField(header)); x;# OM
else 3o%JJIn&
break; 3x#=@i
} VTa?y
} qN1(mxa.?
R)?K+cJ%
ja$e)
public void splitterStop() [9u/x%f(
{ no?TEXp*
bStop = true; f"~+mO
} +M/04
-IMm#
?<YtlqL
} i44UqEb
7v}4 Pl,$4
R0(Nw7!d/[
/* p4\%*ovQt
**FileAccess.java &,4^LFZW
*//文件访问(定位，写) {d.`0v9h
package NetFox; |Vs|&0
import java.io.*; Ua#*kTF
=#[_8)q
GrGgR7eC#P
public class FileAccessI implements Serializable{ t48(,
i,NN"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5r.\maW
RandomAccessFile oSavedFile; y,tA~
long nPos; H'-Fv!l?
7 6~x|6)
X's-i!
public FileAccessI() throws IOException VHsuC$3W
{ c2Ua!p(c
this("",0); I1=YSi;A
} <T[%03
6A7UW7/
%f\ M61Z
public FileAccessI(String sName,long nPos) throws IOException E1_FK1*V;
{ 2mP| hp?
oSavedFile = new RandomAccessFile(sName,"rw"); /7De.O~H
this.nPos = nPos; =i~/.Nu&
oSavedFile.seek(nPos); dGAthbWJ
} l7Y^C1hM
5m&{f>]T
v_J\yW'K
public synchronized int write(byte[] b,int nStart,int nLen) o^wj_#ai$
{ j_-$xz5-
int n = -1; - o$S=
try{ (k"|k
oSavedFile.write(b,nStart,nLen); vQ^a7
n = nLen; PorBB7iL
} k2sb#]-/}
catch(IOException e) H6 ( ~6Bp5
{ B< P H7
e.printStackTrace (); d~tG#<^`
} M6vW}APH[n
j)Zi4<./
i >Hh_q;'
return n; O?p.kf{b
} cpz}!D
jb$sIZ%i
G1 %c<1Y
} 2f]:n
EMU~gwPR
3!`Pv ?|o
/* Jg/l<4,K,
**SiteInfoBean.java %1<No/
*/ x-:vpv%6y
package NetFox; h ^g"FSzP
7=0uG
us\@n"
public class SiteInfoBean { n=MdbY/k(
I>k3X~cG
8s-RNA>7^
private String sSiteURL; //Site's URL Gy.<gyK9
private String sFilePath; //Saved File's Path S;M'qwN
private String sFileName; //Saved File's Name N*$<Kjw
private int nSplitter; //Count of Splited Downloading File x~!B.4gT2
]|<PV5SY3.
V:9|9$G
public SiteInfoBean() J4 .C"v0a
{//nSplitter的缺省值为5 [Tby+pC
//default value of nSplitter is 5 ~;_]U[eOL
this("","","",5); GeWB"(t
} E)3B)(@&P
PvBx<i}A
18z{d9'F
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p<Wb^BE
{ %h=)>5-T
sSiteURL= sURL; kXzm
sFilePath = sPath; g2L
sFileName = sName; AT}}RE@vq
this.nSplitter = nSpiltter; 5Qd |R
5)' _3r
#`RYKQwB
} =xQ7:TB
fs&J%ku\
A9qCaq{
public String getSSiteURL() ^+oi|y
{ oF,XSd
return sSiteURL; 9"52b9U
} LO[1xE9
eW"i'\`0
?aEBS
public void setSSiteURL(String value) 'Y(#Yxc
{ gP/[=:
sSiteURL = value; %E?:9. :NJ
} QIQB
[6K2V:6:
>/;\{IG Wn
public String getSFilePath() \NhCu$'
{ q -M&f@Il
return sFilePath; >"jV8%!sM
} /*`BGNkYY
!CtY.Lp
Ziuf<X{
public void setSFilePath(String value) nQdNXv<(
{ k(C?6Gfj
sFilePath = value; [q cT?h
} `IOp*8
MVg`6&oH
NLyvi,svS
public String getSFileName() M$ep.<Z1|
{ .{k(4_Q?I
return sFileName; TP{lt6wws(
} 2FD[D`n]f
tBtJRi(
nT`NfN
public void setSFileName(String value) I{<6GIU+
{ kQC>8"
sFileName = value; B}X C
} N?Mmv|
7U:,:=
7loCb4Hv
public int getNSplitter() BnvUPDT&
{ VD/Wl2DK
return nSplitter; )wP0U{7?v
} }r]WB)_w
r/HKxXT
s#`%c({U|
public void setNSplitter(int nCount) SW(7!`
{ t!c8c^HR
nSplitter = nCount; aQCbRS6
} vY *p][$
} n} GIf&
:>nk63V (
ioi0^aM
/* l<PGUm:_
**Utility.java THJ KuWy
*/ &YO5N4X~o
package NetFox; j8zh^q
-?e~dLu
ABNsi$]r0
public class Utility { XtT;UBE
Bh:AY@k
j8?$Hk
public Utility() TUJ]u2J8?
{ W2|*:<Jt
CWE jX-
eM/|"^%
} C@pDX>~2=b
-4,qAnuMx
//线程睡眠 nuw90=qj!]
public static void sleep(int nSecond) Id]WKL:
{ SjKIn-
try{ 3 C=nC
Thread.sleep(nSecond); -}{\C]%
} cmt3ceCb
catch(Exception e) .Y_RI&B!L
{ tH5f;mY,
e.printStackTrace (); \@pl:Os
} [4kx59J3b
} :|<D(YA
lcJ`OLG
//日志 hOfd<k\A
public static void log(String sMsg) fB1JU1
{ ]j*o&6cQf
System.err.println(sMsg); zVxiCyU
} [H0jDbN
tFwQ /
\b.2f+;3
public static void log(int sMsg) "M7ry9dDH
{ Lr)h>j6\
System.err.println(sMsg); L]9!-E
} m4E 6L
} s[nOB0
1:My8
cIl^5eE^Pq
/* `!qWHm6I*
**TestMethod.java ;ZjQy,H%
*/ RduA0@g0
package NetFox; (d^pYPr{
~S|Vd
,U>g LTS
public class TestMethod { #$jAGt3^BT
[+{ ot
/Ia=/Jj7N
public TestMethod() n+zXt?{u
{ ///xx/weblogic60b2_win.exe TnM}|~V
try{ +/\.%S/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =!U{vT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); VQPq+78
SiteFileFetch fileFetch = new SiteFileFetch(bean); w#Nn(!VR
fileFetch.start(); ~Ufcy{x#
} &_" 3~:N8k
catch(Exception e){e.printStackTrace ();} \5s!lv*&
p]!,BoZL
t=XiSj\n
} l3-KswU
LrF'Hd=O
?e3q0Lg3|
public static void main(String[] args) L}>9@?;GW
{ 4DuZF -y
new TestMethod(); En5Bsz!
} m|24)%Vj;=
} t~5>PS
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