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)); :6[G;F7s
} 5!Ho[
for(int i=0;i<nEndPos.length-1;i++) !+V."*]l
{ D_)N!,i
nEndPos = nStartPos[i+1]; !(8)'<t9
} IDK~ (t
nEndPos[nEndPos.length-1] = nFileLength; Xf%vfAf
} $No^\.mV
} >*]dB|2
N#<X"&-_#
)zv"<>Q 6
//启动子线程 VYw<8AEFY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; k((kx:
for(int i=0;i<nStartPos.length;i++) m>{I>:sq
{ 1/tyne=m
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <Eu/f`8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), JH+uBZh6
nStartPos,nEndPos,i); w/,A@fLL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8I]rC<O6:
fileSplitterFetch.start(); VoC|z Rd_
} 6c[Slq!KA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZU68\cL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q79WGW
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8JojKH
nEndPos = " + nFileLength); 9l<}`/@}W
// fileSplitterFetch[nPos.length-1].start(); k!0vpps
fJK;[*&Y
;;}}uW=
//等待子线程结束 #B6$r/%
//int count = 0; 8'-E>+L
//是否结束while循环 KSve_CBOh
boolean breakWhile = false; 6ee1^>
rKkFflOVO
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while(!bStop) XYze*8xUb
{ qNX+!Y}y
write_nPos(); qoAJcr2uN
Utility.sleep(500); RHu4cK!5
breakWhile = true; RH^;M-'
WiqkC#N
Fgw$;W
for(int i=0;i<nStartPos.length;i++) 5 D[`nU}
{ nU23D@l
if(!fileSplitterFetch.bDownOver) ?6V U4nK/*
{ /}Ct2w&<k
breakWhile = false; PnJA'@x
break; !N74y%=M
} #SR )tU
} 8E|FFHNK<2
if(breakWhile) Bp/k{7
break; TeHxqWx
4hWFgk
Exz(t'
//count++; "P!zu(h4
//if(count>4) xgJyG.?
// siteStop(); p?#xd!tc2N
} +HF*X~},i
Eyh(257
4Ix~Feuph
System.err.println("文件下载结束！"); {k)H.zwe
} I3AxKA
catch(Exception e){e.printStackTrace ();} V>"NVRY
} d(q2gd@
L"'L@A|U
EASN#VG
//获得文件长度 @N6KZn|R
public long getFileSize() nnuJY$O;M
{ b8h6fB:2
int nFileLength = -1; ~EO=;a_
try{ ge[&og/$
URL url = new URL(siteInfoBean.getSSiteURL()); "Xj>dB1~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =/kT|
httpConnection.setRequestProperty("User-Agent","NetFox"); CA3`Ee+rD
6#Bg99c
uiq;{!dop
int responseCode=httpConnection.getResponseCode(); 7 aN}lQM
if(responseCode>=400) 1Ba.'~:
{ ;5:3 =F>ao
processErrorCode(responseCode); l<p6zD$l
return -2; //-2 represent access is error t<yOTVah
} n:[LsbTk
rp!>rM] s
V&R_A~<T
String sHeader; fvM|Jb
vqRW^>~-B
,a\pdEPj
for(int i=1;;i++) ee*E:Ltz\
{ f/pr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WO+_|*&
//Utility.log(in.readLine()); 4p]hY!7
sHeader=httpConnection.getHeaderFieldKey(i); 7Yly^
if(sHeader!=null) /S`d?AV
{ e[%g'}D:-
if(sHeader.equals("Content-Length")) ktiC*|fd
{ K~ VUD(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~c|{PZ9U
break; AUwIF/>F(]
} fHacVjJ
} iYz!:TxP
else p} i5z_tS
break; t**o<p#)f
} 9 [wR/8Xm
} F2CoXe7
catch(IOException e){e.printStackTrace ();} NplkhgSj
catch(Exception e){e.printStackTrace ();} jHpFl4VPz
7_]Bu<{f
?&"!,
Utility.log(nFileLength); pd oCV
J}s)#va9R
*_tJ;
return nFileLength; k1_3\JO"6
} #3((f[
h7[PU^m
nX-%qc"
//保存下载信息（文件指针位置） &+7G|4!y
private void write_nPos() J@Qw6J
{ psAdYEGk!
try{ yWZ%|K~$
output = new DataOutputStream(new FileOutputStream(tmpFile)); qb$f,E[
output.writeInt(nStartPos.length); P*6&0\af|
for(int i=0;i<nStartPos.length;i++) MUqV$#4@I
{ (C!33s1
// output.writeLong(nPos); -,}ppTG
output.writeLong(fileSplitterFetch.nStartPos); 'E~[I"0
output.writeLong(fileSplitterFetch.nEndPos); 2Ls
} \7A6+[ `fa
output.close(); m'ykDK\B
} *m`KY)b=l
catch(IOException e){e.printStackTrace ();} Auf2JH~
catch(Exception e){e.printStackTrace ();} L }&$5KiwV
} wEJ?Y8
/]"2;e-s+
y w>T1
//读取保存的下载信息（文件指针位置） "ju0S&
private void read_nPos() Dv[ 35[Yh
{ t"]~e"
try{ %2TjG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XV*uu "F
int nCount = input.readInt(); tS&rR0<OW
nStartPos = new long[nCount]; mLL?n)
nEndPos = new long[nCount]; +)l6%QKcW
for(int i=0;i<nStartPos.length;i++) V-%Am
{ gTwxmp.,
nStartPos = input.readLong(); >$p|W~x
nEndPos = input.readLong(); cQldBc
} l]v>PIh~N
input.close(); |HMpVT-;j
} >s+*D=k
catch(IOException e){e.printStackTrace ();} $r87]y!
catch(Exception e){e.printStackTrace ();} E0a &1j
} s6J`i&uu
8^%Nl `_2B
isR|K9qf^
private void processErrorCode(int nErrorCode) '{xPdN
{ #iAEcC0k5
System.err.println("Error Code : " + nErrorCode); Wf>scl`s
} a'2^kds
$C8nPl' 7
Wa+q[E
//停止文件下载 V_Oj?MMpn
public void siteStop() >gFEA0-
{ =g+Rk+jn
bStop = true; ]EZiPW-uy
for(int i=0;i<nStartPos.length;i++) MUfhk)"
fileSplitterFetch.splitterStop(); @>sZ'M2mq
JM-+p
Yx{qVU
} 9akIu.H
} _r&,n\ T
//负责部分文件的抓取 !*@sX7H
**FileSplitterFetch.java xf]_@T;
*/ a@&P\"k
package NetFox; O#962\
y}t1r |p
oWo/QNw9
import java.io.*; &KS*rHgt?
import java.net.*; H~Fb=.h]U
kKP<K+hH
xLmgr72D
public class FileSplitterFetch extends Thread { 5g(`U+,*(
o)pso\;
>l3iAy!sZ
String sURL; //File URL <|MF\D'
long nStartPos; //File Snippet Start Position QZs ]'*=#
long nEndPos; //File Snippet End Position aEW sru
int nThreadID; //Thread's ID =~f\m:Y
boolean bDownOver = false; //Downing is over 1||\3L/
boolean bStop = false; //Stop identical mjtmN0^SR
FileAccessI fileAccessI = null; //File Access interface e7^B3FOx
kg^VzNX
qu:nV"~_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F+3}Gkn
{ Lradyo44u\
this.sURL = sURL; |kXx9vGq@
this.nStartPos = nStart; c/Ykk7T9--
this.nEndPos = nEnd; z[`OYwsW
nThreadID = id; -]K9sy)I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 FELDz7DYya
} Btgxzf
~l@ h
NP#:} )
public void run() kED1s's
{ 7}2Aq
while(nStartPos < nEndPos && !bStop) B<" `<oG@|
{ BrO" _
_^5OoE"}!
gx',~
try{ p2/Pj)2
URL url = new URL(sURL); TC+L\7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R]! [h
httpConnection.setRequestProperty("User-Agent","NetFox"); -)p S\$GC
String sProperty = "bytes="+nStartPos+"-"; hmQ;!9
httpConnection.setRequestProperty("RANGE",sProperty); L H8iHB
Utility.log(sProperty); ;0c -+,
NM{/rvM
iUua!uC
InputStream input = httpConnection.getInputStream(); (Iz$_(
//logResponseHead(httpConnection); =h Lw1~
/eO:1c
r$ 8^K\oF
byte[] b = new byte[1024]; >{HQ"{Q
int nRead; 3\B28m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Y%1 94fY$
{ -0>gq$/N=^
nStartPos += fileAccessI.write(b,0,nRead); KW1b #g%Z
//if(nThreadID == 1) }@XokRk
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JE<w7:R&
} [<,i}z
+M=`3jioL
<lo\7p$A
Utility.log("Thread " + nThreadID + " is over!"); #@3&1}J/
bDownOver = true; n,_q6/!
//nPos = fileAccessI.write (b,0,nRead); OkV*,n
} 3Hd~mfO\
catch(Exception e){e.printStackTrace ();} &{uj3s&C
} U7do,jCoa
} hRwj-N%C
r&/M')}?Lw
9{KL^O?g
//打印回应的头信息 \~!!h.xR
public void logResponseHead(HttpURLConnection con) TF1,7Qd
{ ]~K&b96(
for(int i=1;;i++) ~EL3I
{ MOia]5
String header=con.getHeaderFieldKey(i); rijavZS6
if(header!=null) V*<`!w
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fFYfb4o
Utility.log(header+" : "+con.getHeaderField(header)); y<5RV>"Vg
else $~+(si2
break; a-bj! Rs
} Pb`Uxv
} B8~JUGD
X;&Iu{&=
<c77GimD?
public void splitterStop() QB.QG!@
{ W2Ik!wEe&
bStop = true; "\k|Z
} JuKG#F#,
|W#(+m
6Lc{SR
} [2$mo;E?
?`lD|~
\5iMr[s
/* RH}i=
**FileAccess.java mfqnRPZ
*//文件访问(定位，写) ;0vCZaEF
package NetFox; L~+/LV
import java.io.*; \}Al85
hl]q6ZK!6
9]Fi2M
public class FileAccessI implements Serializable{ 'CMbqLk#
U #C@&2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \_]X+o;
RandomAccessFile oSavedFile; SNJSRqWL/
long nPos; dM=45$\q
J6I:UML
jP{&U&!i
public FileAccessI() throws IOException yiw4<]{IX
{ `+m:@0&L
this("",0); y '[VZ$^i
} Gl"|t't(
N<PDQ
0MI4"<
public FileAccessI(String sName,long nPos) throws IOException .0Kc|b=w
{ YSh@+AN
oSavedFile = new RandomAccessFile(sName,"rw"); D"V(A\sZ
this.nPos = nPos; s(Bcw`'#
oSavedFile.seek(nPos); )Yu
} uc>":V
jNvDE}'
w*M&@+3I
public synchronized int write(byte[] b,int nStart,int nLen) %E\zR/
{ $<QrV,T
int n = -1; d%za6=M
try{ bFIM07
oSavedFile.write(b,nStart,nLen); [=BccT:b
n = nLen; ,gpZz$Ef(
} _a#k3r
catch(IOException e) 4_`(c1oA
{ u4h0s1iI
e.printStackTrace (); ^)y8X.iO
} AP1&TQ,&
rQxiG[0
"<"m}rE?Q
return n; e }Mf
} r7,}"Pl
^)(-7H
B<Q)z5KK
} 0NeIQr1N_
^TtL-|I
3vs{*T"
/* 0|Xz-Y
**SiteInfoBean.java W,|+Dl
*/ FUarI5#fwF
package NetFox; h 8xcq#
{h=gnR-9
84WX I#BH
public class SiteInfoBean { >%ovL8F
c: r25
RfOJUz
private String sSiteURL; //Site's URL 6O<UW.
private String sFilePath; //Saved File's Path 1<Sg@
private String sFileName; //Saved File's Name f14^VTzP/#
private int nSplitter; //Count of Splited Downloading File aeISb83Y|
}T0O~c{$i
8t3m$<7
public SiteInfoBean() Khb Ku0Z
{//nSplitter的缺省值为5 AhD C5ue=
//default value of nSplitter is 5 jU $G<G
this("","","",5); sH.=Faos
} _jc_(;KPF
O%3Hp.|!
<PVwf`W.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |UlG@Mn
{ o@BV&|
sSiteURL= sURL; !> =ybRe
sFilePath = sPath; 64mg:ed&
sFileName = sName; 8IA1@0n&
this.nSplitter = nSpiltter; /)T~(o|i
Cs_&BSs
}jUsv8`}8R
} M.K^W`
D<m0G]Ht*
J\Hv42
public String getSSiteURL() *i}X(sfe
{ qiB~
return sSiteURL; D#G%WT/"
} >{N}UNZ$}
CxTmW5l
oNtoqYwH
public void setSSiteURL(String value) fd4C8>*7G
{ #1/~eIEY
sSiteURL = value; V^,eW!
} gfs;?vP
zGFD71=#
@zC6`
public String getSFilePath() d\ 8v VZ
{ F~8'3!<9
return sFilePath; R0}1:1}$Sn
} WFiX=@SS
s(nT7x+W
b,^Gj]7
public void setSFilePath(String value) 0|RofL&o
{ ?+))J~@t
sFilePath = value; D3yTN"
} +rJ6DZ
."H;bfcL_
bx(@ fl:m
public String getSFileName() 8[KKi~A
{ ] \M+ju
return sFileName; @uH!n~QV
} y-db CYMc
c7jmzo
>;^/B R=
public void setSFileName(String value) (Kwqa"Hk4{
{ ~g\~x
sFileName = value; aknIrblS\
} &yvvea]
F)(^c
0eNdKE
public int getNSplitter() %W"u4 NT7
{ uMEM7$o
return nSplitter; ? Bpnnwx
} a$"nNmD?
g5|~i{"0
oGRk/@
public void setNSplitter(int nCount) )Cl>%9
{ %+H_V1F
nSplitter = nCount; 3l~+VBR_
} lcie6'<
} `UTPX'Vz
d/bimQ
4LKpEl.=
/* x-m*p^}
**Utility.java T@tsM|pI
*/ (T_-`N|
package NetFox; ~=*o
3uocAmY
z.Ic?Wz7
public class Utility { bGCC?}\
1EXT^2!D
>jX"
public Utility() &t^*0/~
{ c|k_[8L
2n,z`(=
&{V|%u}v
} `Pvi+:6\Y
8f9wUPr
//线程睡眠 Hw o _;fV
public static void sleep(int nSecond) [(heE
{ %dzt'uz
try{ TP rq:"K
Thread.sleep(nSecond); NX&dJ 6a
} uQIPnd(V
catch(Exception e) ?>}p'{I
{ Nvgi&iBh8
e.printStackTrace (); YGJ!!(~r
} hSm?Z!+
} Hz.i$L0}
t1Fqq4wRi
//日志 xoKK{&J
public static void log(String sMsg) 7GOBb|
{ -G.N
System.err.println(sMsg); ]p`y
} l8FJ\5'M
G*I
s<zN`&t
public static void log(int sMsg) lxyTh'
{ )8A.Wg4S;c
System.err.println(sMsg); &DWSf`:Hx
} N4vcd=uG#
} EB}B75)x
CPJ21^
;k!.ey$S
/* `;j1H<L
**TestMethod.java uO]D=Z\S(
*/ ~#E&E%sJ
package NetFox; q[\3,Y
,^([aK
,<U= 7<NU
public class TestMethod { 98Vv K?
p(n0(}eVC'
~6f/jCluR%
public TestMethod() G'\[dwD,u
{ ///xx/weblogic60b2_win.exe yv4x.cfI2W
try{ \6|y~5Hw{r
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1eD#-tzV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pTCD1)
SiteFileFetch fileFetch = new SiteFileFetch(bean); K=N&kda
fileFetch.start(); dHDtY$/_
} nK;d\DO
catch(Exception e){e.printStackTrace ();} y|| n9
9i\RdJv.
6\.g,>
} 3+Lwtb}XPF
Gd 4S7JE
f6Y?),`
public static void main(String[] args) I6^y` 2X
{ |HycBTN#E
new TestMethod(); OkciL]
} =3035{\
} nX (bVT4i
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