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)); Hjm> I'9
} zp}7p~#k^
for(int i=0;i<nEndPos.length-1;i++) p<5]QV7st
{ Q((&Q?Vi
nEndPos = nStartPos[i+1]; sxNf"C=-.
} [D"6&
nEndPos[nEndPos.length-1] = nFileLength; )+_Vx}O:}
} htBA.eQ
} dyQ7@K.E
)lG}B U.
UG2+Y']
//启动子线程 yE:y[k0E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |E8sw a
for(int i=0;i<nStartPos.length;i++) y=Y k$:-y
{ Q]WBH_j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]A5F}wV4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]LvP)0=
nStartPos,nEndPos,i); =pL$*`]?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Nq8ON!<<
fileSplitterFetch.start(); (TZK~+]@sb
} "qmSwdM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *C_A(n5"V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); q/s-".%P
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K=gg<E<
nEndPos = " + nFileLength); #C9f?fnM
// fileSplitterFetch[nPos.length-1].start(); f_~T
;hT3N UCA
,/f\
//等待子线程结束 kWr1>})'
//int count = 0; &~:EmLgv
//是否结束while循环 Ip t;NlR
boolean breakWhile = false; j.=:S;
?8~l+m6s$
9UM)"I&k
while(!bStop) H:.~! r
{ v "l).G?
write_nPos(); u?,>yf.;s
Utility.sleep(500); X!KX4H
breakWhile = true; HPtMp#`T
q{w|`vIb
Ed=/w6<
for(int i=0;i<nStartPos.length;i++) +hRy{Ps/
{ 2E*=EjGV
if(!fileSplitterFetch.bDownOver) 8m+~HSIR
{ +SFFwjI
breakWhile = false; k4{!h?h
break; Ej(BE@6>s
} b|i4me@
} ~XR('}5D
if(breakWhile) |lNp0b
break; |4+'YgO
Ag8/%a~(
Xu-~j!
//count++; [N,+mX
//if(count>4) 7$*E0
// siteStop(); Tvv>9gS
} ]]|#+$ ~
SdnnXEB7
)Jt. Z^J<
System.err.println("文件下载结束！"); , z\Qd07u
} ]L3U2H`7
catch(Exception e){e.printStackTrace ();} WJ8i=MO67
} JD*HG]
^Gk)aX
<X*oW".
//获得文件长度 & AK\Pw)
public long getFileSize() ]!ai?z%cK#
{ {V7mpVTX.
int nFileLength = -1; (wu'FFJp#
try{ Kw-<o!~
URL url = new URL(siteInfoBean.getSSiteURL()); AZ.QQ*GZ#y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d9[j4q_
httpConnection.setRequestProperty("User-Agent","NetFox"); YP,,vcut
a;[\nCK
EjfQF C
int responseCode=httpConnection.getResponseCode(); EV6R[2kl
if(responseCode>=400) B EwaQvQ!
{ 7;Ze>"W>
processErrorCode(responseCode); +3o vO$g
return -2; //-2 represent access is error 2/3yW.C
} 1uw1(iL+
.=:f]fs
A;8kC}
String sHeader; jU-LT8y:
3I 0pHP5
+.Vh<:?
for(int i=1;;i++) <y7{bk~i
{ db 99S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >_j(uw?u
//Utility.log(in.readLine()); x<I[?GT=
sHeader=httpConnection.getHeaderFieldKey(i); 3$"V,_TBZ
if(sHeader!=null) G$,s.MSf
{ ZV{C9S&
if(sHeader.equals("Content-Length")) {XU!p: x
{ l2;$qNAo
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b@J"b(
break; N[eLQe]q
} k -G9'c~
} /T6bc^nOW
else *Xnf}Ozx
break; ?=lb@U
} U-DQ?OtmC@
} vyS>3(NZ
catch(IOException e){e.printStackTrace ();} =cRmaD
catch(Exception e){e.printStackTrace ();} 2Pb+/1*ix
d5-Q}D,P
PxYK)n9&
Utility.log(nFileLength); h GA2.{
rn .qs
T[4xt,[a
return nFileLength; @7}XBg[pI
} 0d2RB^"i
Rir0^XqG
l^I?@{W
//保存下载信息（文件指针位置） >V8!OaY5n
private void write_nPos() |6^a[x3/U
{ <yl@!-'J7
try{ oL9<Fi
output = new DataOutputStream(new FileOutputStream(tmpFile)); $-/-%=
output.writeInt(nStartPos.length); c) Eu(j\#
for(int i=0;i<nStartPos.length;i++) 8(j]=n6r
{ XOX$uLm
// output.writeLong(nPos); 4x ?NCD=k
output.writeLong(fileSplitterFetch.nStartPos); ], Bafz)4
output.writeLong(fileSplitterFetch.nEndPos); 2{RRaUoRb
} t{UVX%b
output.close(); uKzx >\}?1
} )xf(4
catch(IOException e){e.printStackTrace ();} %UdE2D'bC
catch(Exception e){e.printStackTrace ();} x#E M)Thq
} ;|K }
i;pg9Vw
'bRf>=
//读取保存的下载信息（文件指针位置） G1it 3^*$
private void read_nPos() iJdJP)!tz6
{ 1PxRj
try{ kKRu]0J~[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); . AA# G
int nCount = input.readInt(); < e3] pM
nStartPos = new long[nCount]; L[PqEN\i
nEndPos = new long[nCount]; )'jGf;du
for(int i=0;i<nStartPos.length;i++) BHp>(7,
{ ] K&ca
nStartPos = input.readLong(); H.M: cD:
nEndPos = input.readLong(); `yq) y>_
} pS-o*!\C.
input.close(); &LI q?
} n<|8Onw
catch(IOException e){e.printStackTrace ();} gna!Q
catch(Exception e){e.printStackTrace ();} q=e;P;u
} <zY#qFQ2
V|A.M-XLv4
8m H6?,@6
private void processErrorCode(int nErrorCode) +Y*4/w[
{ =mQY%l
System.err.println("Error Code : " + nErrorCode); aNM*=y`
} Q0`@=5?-
}+lK'6
fFVQu\
//停止文件下载 hQ>$"0K
public void siteStop() {{gd}g
{ k6DJ(.n'%a
bStop = true; IM6n\EZ^
for(int i=0;i<nStartPos.length;i++) +z9BWo!{I
fileSplitterFetch.splitterStop(); Q(x=;wf5r
Jv 5l
p]X+#I<
} /(||9\;
} c='W{47
//负责部分文件的抓取 $Vp&7OC]
**FileSplitterFetch.java ^{J^oZ'%~
*/ 44n41.Q]
package NetFox; [ s/j?/9
-mO<(wfV>
~eTp( XG
import java.io.*; T__@hfT
import java.net.*; 1Z_]Ge<a
PRYm1Y
k^JgCC+
public class FileSplitterFetch extends Thread { r#j3O}(n
h`Ej>O7m
=|O]X|y-lZ
String sURL; //File URL >yenuqIKQv
long nStartPos; //File Snippet Start Position b* n#XTV
long nEndPos; //File Snippet End Position H9_>a-> )~
int nThreadID; //Thread's ID LkafB2y
boolean bDownOver = false; //Downing is over Eb5>c/(
boolean bStop = false; //Stop identical ?st}rJ_
FileAccessI fileAccessI = null; //File Access interface ?3LV$S)U
uFuH/(}K[
Pvv7|AV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _;BNWH
{ ^eoW+OxH
this.sURL = sURL; R/B/|x
this.nStartPos = nStart; }#g &l*P
this.nEndPos = nEnd; V/\`:
nThreadID = id; l YdATM(h
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \2f?)id~
} taVK&ohWx
OvC@E]/+
1*#hIuoj'
public void run() mWoN\Rwj
{ &f A1kG%
while(nStartPos < nEndPos && !bStop) lZ"C~B}9:I
{ '&|%^9O/"
$^e_4]k
p&xj7qwp@F
try{ SRHD"r^@
URL url = new URL(sURL); f/kYm\Zc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #~rQ\A!4
httpConnection.setRequestProperty("User-Agent","NetFox"); ,o `tRh<
String sProperty = "bytes="+nStartPos+"-"; ,rY}IwMw
httpConnection.setRequestProperty("RANGE",sProperty); HA$7Q~{N-t
Utility.log(sProperty); _=[pW2p
E^w0X,0XlE
P$O@G$n
InputStream input = httpConnection.getInputStream(); =L"I[
//logResponseHead(httpConnection); e=tM=i"
Z0~,cO8~
~T._v;IT
byte[] b = new byte[1024]; iF:NDqc
int nRead; 'L1yFv
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ncsk(`lo
{ m,4'@jg0
nStartPos += fileAccessI.write(b,0,nRead); k9y/.Mu
//if(nThreadID == 1) 0!c/4^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DM,;W`|6%
} *rm[\
rd(-2,$4
\u/=?b
Utility.log("Thread " + nThreadID + " is over!"); UBuG12U4Y
bDownOver = true; <qoPBm])
//nPos = fileAccessI.write (b,0,nRead); c!$~_?]
} Tz(Dhb,
catch(Exception e){e.printStackTrace ();} {v3@g[:|
} MzW!iG
} ~vZ1.y4
TYxi&;w
Pl|*+g
//打印回应的头信息 cnDBT3$~Z
public void logResponseHead(HttpURLConnection con) naY#`xig
{ nrTCq~LO(
for(int i=1;;i++) 2Y}A9Veb
{ esv<b>`R
String header=con.getHeaderFieldKey(i); qm=9!jqC;
if(header!=null) ,+5!1>\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .KYDYdoS'
Utility.log(header+" : "+con.getHeaderField(header)); ^'vWv C
else ,y7X>M2
break; (WGEX(|
} H[/^&1P
} 2ZxZ2?.uJ
DY87NS*HF
Ban"H~
public void splitterStop() NA$ODK-
{ <U/r U9O
bStop = true; tgrZs8?
} !6+V
/jU4mPb;\D
- :x6X$=
} Pv$O=N6-
;4vx+>-
?l 0WuU
/* Nu; 9
**FileAccess.java cl'qw##
*//文件访问(定位，写) 0te[i*G
package NetFox; $O9#4A;
import java.io.*; M[Jy?b)
!;U}ax;AF
< $rXQ
public class FileAccessI implements Serializable{ J\ ?
LC/%AbM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C:}"?tri
RandomAccessFile oSavedFile; .18MMzdN
long nPos; ];Bk|xJ/>
Or()AzwE@
kPp7;U2A
public FileAccessI() throws IOException 6)3pnhG9
{ |=Pw-uk
this("",0); ^+dL7g?+
} eG5xJA^
KlRIJOS
yu'@gg(
public FileAccessI(String sName,long nPos) throws IOException ?CuwA-j
{ MJ@PAwv"
oSavedFile = new RandomAccessFile(sName,"rw"); dMH}%f5;1
this.nPos = nPos; S?(/~Vb%
oSavedFile.seek(nPos); H[iR8<rhQ
} KQrG|<J
!*-|s}e
Jpo(O>\P
public synchronized int write(byte[] b,int nStart,int nLen) NFb<fD[C
{ %t,Fxj4F
int n = -1; AhSN'gWpbF
try{ &;%LTF@I,
oSavedFile.write(b,nStart,nLen); E"Y[k8-:2/
n = nLen; Ivc/g,
} V)Y#m/$`
catch(IOException e) h!]=)7x;
{ i}LVBx"K(
e.printStackTrace (); $%3%&+z$I
} ,y*|f0&"~
$[*<e~?
DqBiBH[%h
return n; mp>Ne6\Tu
} ,A!0:+
p+1kU1F0
Sa$-Yf
} Eg#WR&Uq"
ksli-Px
^/$bd4,z
/* kt hy9<!$
**SiteInfoBean.java m2PI^?|e
*/ `9p;LZC1K
package NetFox; eq$.np
|Skhx9};
rTtxmw0
public class SiteInfoBean { B["C~aF
2GBE=T
X?OH//co
private String sSiteURL; //Site's URL .0'FW!;FV
private String sFilePath; //Saved File's Path .L}k-8
private String sFileName; //Saved File's Name 5g;i{T/6~x
private int nSplitter; //Count of Splited Downloading File #qdfr3
CR'1,
c\(CbC
public SiteInfoBean() &X OFc.u
{//nSplitter的缺省值为5 j.7BoV
//default value of nSplitter is 5 VPXUy=W
this("","","",5); X< p KAO\
} !"QvV6Lq\
Xg1QF^
o",J{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _ "H&
{ y^hCO:`l3
sSiteURL= sURL; p`06%"#
sFilePath = sPath; c R6:AGr
sFileName = sName; 1gDsL
this.nSplitter = nSpiltter; +I r
C7T}:V](q
zqa7!ky
} FWDAG$K@0
v<tr1cUT
J'Y;j^
public String getSSiteURL() S;I}:F#5
{ [,/~*L;7
return sSiteURL; ^s?=$&8f![
} )TzQ8YpO}
,\=,,1_
n]fMl:77
public void setSSiteURL(String value) {E$smX
{ 6k*,Yei
sSiteURL = value; R*r;`x
} @pO2A6Ks
wOs t).
I7e.pm
public String getSFilePath() D $3Mg
{ 6$A>%Jtwe
return sFilePath; Dt=@OZW
} KetNFwbUf
:2(U3~3:
8zzY;3^h;
public void setSFilePath(String value) `(o:;<&3
{ }GL@?kAGR5
sFilePath = value; zX}t1:nc
} B'8/`0^n5
5l4YYwd>v
G#nZ%qQ:I
public String getSFileName() 5V@c~1\
{ 'j(F=9)
return sFileName; yttaZhK^u
} kBg8:bo~
)uu1AbT+e
P:&X1MC
public void setSFileName(String value) = 4 wf
{ ?Es(pwJB
sFileName = value; YML]pNB
} bfXyuv
u4vyj#V
uJ T^=Y
public int getNSplitter() iqr/MB,W
{ omzG/)M:O
return nSplitter; Z|$M 9E
} x ?24oO
}ej>uZVe<
&hu>yH>j
public void setNSplitter(int nCount) ;{89*e*)
{ F_F02:t
nSplitter = nCount; !8*lU2
} wGg_ vAn
} FS^~e-A
Ra/Pk G-7
VDTt}J8
/* 7m:ZG
**Utility.java cB=ExD.Q
*/ Lz{z~xNHW.
package NetFox; <NXJ&xs-+
{ep(_1
Oe ~g[I;
public class Utility { D$Eq~VQ
yc+pNC)ue_
~sT1J|
public Utility() AW8*bq1
{ B;e (5y-
03H0(ku=
y4)iL?!J~
} M>[e1y>7
Hg5:>?Lw@
//线程睡眠 +h08uo5c
public static void sleep(int nSecond) nM|Cv
{ E.N
try{ #f<3[BLx
Thread.sleep(nSecond); S`8Iu[Ma
} Z5|BwM
catch(Exception e) );;UA6CD
{ .F},Z[a&
e.printStackTrace (); T/]f5/
} Z7XFG&@6
} gVNoC-n)
F.),|t$\
//日志 KX J7\}
public static void log(String sMsg) 2F :8=_sA
{ gCq'#G\Z
System.err.println(sMsg); T>68 ,; p
} ,&.$r/x|?
>#VNA^+t
^B:;uyG]M
public static void log(int sMsg) VwOcWKD
{ JED\"(d(
System.err.println(sMsg); < 1[K1'7h
} \@[,UZ
} BU#3fPl
e|N~tUVrrN
>L')0<!&
/* +pRNrg?k
**TestMethod.java GZ^Qt*5 {
*/ YPW UncV
package NetFox; *:"@
mv7W03
dXfLN<nD>U
public class TestMethod { &~=r .T
Zm0'p!
5] LfJh+"n
public TestMethod() ,Qs%bq{t
{ ///xx/weblogic60b2_win.exe LcZ|A;it
try{ "T9UedZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !2h ZtX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6?'7`p
SiteFileFetch fileFetch = new SiteFileFetch(bean); t{s*,X\b
fileFetch.start(); k!Q{u2
} q=}1ud}1
catch(Exception e){e.printStackTrace ();} DD2K>1A1
.+,U9e:%
>n^780S|
} T*nP-b
&r\8VEZq"
|Ve,Y
public static void main(String[] args) 5vg="@O K
{ (zh[1[a
new TestMethod(); tva=DS
} oC-v>&bW
} yzv"sd[8N
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