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> y!
} _1G/qHf^S
for(int i=0;i<nEndPos.length-1;i++) ]7W!f 2@
{ DAWF =p]
nEndPos = nStartPos[i+1]; /Z^a,%1
} 87l*Y|osP
nEndPos[nEndPos.length-1] = nFileLength; A~a 3bCX+"
} mKO~`Wq%@
} [5p9p1@u{C
]3Ia>i
!Ea!"}
//启动子线程 Q`AlK"G,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1#_pj eG
for(int i=0;i<nStartPos.length;i++) FauASu,A
{ sa o&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zM&ro,W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :AztHf?X
nStartPos,nEndPos,i); ~<VxtcEBz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w$f_z*/
fileSplitterFetch.start(); HSG Ln906
} H6 x
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y3:HQ0w`|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W)Y`8&,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6&SNFOX{@
nEndPos = " + nFileLength); zytN leyc
// fileSplitterFetch[nPos.length-1].start(); Q2m[XcnX
m6BUKX\m
~210O5^
//等待子线程结束 eu$VKLY*
//int count = 0; 9 CZ@IFS
//是否结束while循环 -kLBq:M
boolean breakWhile = false; h092S|iY
<H60rON
0O`Rh"O
while(!bStop) yVK ; "
{ N^oP,^+U
write_nPos(); HLPRTta.
Utility.sleep(500); Fh)xm* u(
breakWhile = true; gF)-Ci
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dyn)KDS
for(int i=0;i<nStartPos.length;i++) ~%>i lWaHB
{ 0$Rn|yqf%
if(!fileSplitterFetch.bDownOver) ~\NQkaBkY
{ |Vz)!M
breakWhile = false; ms}o[Z@n
break; q`2dL)E
} ">wvd*w0"(
} e7xv~C>g
if(breakWhile) o}KVT%}
break; w@,p`
?B ,<gen
7!jb
//count++; F6yFKNK!n
//if(count>4) pIK:$eN!/
// siteStop(); fG>3gS6&
} *Ts$Hj[
Q}B]b-c+E
\a;xJzc9
System.err.println("文件下载结束！"); -avxH?;?7
} >e6OlIW
catch(Exception e){e.printStackTrace ();} ]h`*w
} 18F}3t??
8o|C43Q_
;AOLbmb)H4
//获得文件长度 =bD.5,F)
public long getFileSize() ya~;Of5
{ T=-UcF
int nFileLength = -1; M}11 tUl
try{ |A*4Fuc&
URL url = new URL(siteInfoBean.getSSiteURL()); v^o`+~i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D^%IFwU^
httpConnection.setRequestProperty("User-Agent","NetFox"); X5.9~
GBBr[}y-
LhAW|];
int responseCode=httpConnection.getResponseCode(); 3h.,7,T
if(responseCode>=400) zC)JOykI%
{ oc,I,v
processErrorCode(responseCode); |T"vF`Kr(>
return -2; //-2 represent access is error /"La@M37
} Iv
<]G'& iv>
iLBORT!;
String sHeader; &)Qq%\EP4
_p:n\9k
v?]a tb/h`
for(int i=1;;i++) F68eI%Y
{ hL/u5h%$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Rf`_q7fm
//Utility.log(in.readLine()); 9rz$c, Y(
sHeader=httpConnection.getHeaderFieldKey(i); 'q:7PkN!p
if(sHeader!=null) IowXVdm@6
{ 084Us s
if(sHeader.equals("Content-Length")) T<Xw[PEnP
{ Yu" Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); oCkG
break; VV1sadS:S`
} Ow>u!P!
} K5LJx-x*j
else diu"Nt
break; pEcYfj3M
} 2C:u)}R7D
} 7:LEf"vRZ
catch(IOException e){e.printStackTrace ();} Z|*#)<|~
catch(Exception e){e.printStackTrace ();} l9|K,YVW
E]n]_{BN]
HEFgEYlO
Utility.log(nFileLength); ;Z0&sFm
O0'|\:my
/hqn>t
return nFileLength; Z_bVCe{
} VS ECD;u4c
uZL,%pF3A
K!9K^h
//保存下载信息（文件指针位置） U'F}k0h?\'
private void write_nPos() dO2?&f
{ <S7SH-{_\
try{ j$_?g!I=gK
output = new DataOutputStream(new FileOutputStream(tmpFile)); q 6UZ`9&z
output.writeInt(nStartPos.length); lbt8S.fx
for(int i=0;i<nStartPos.length;i++) D1-w>Y#
{ pm=O.)g4`
// output.writeLong(nPos); R2~y<^.V`Y
output.writeLong(fileSplitterFetch.nStartPos); 5>%^"f
output.writeLong(fileSplitterFetch.nEndPos); U`3?bhzua
} x^)?V7[t
output.close(); xa'U_]m
} J/Y9X,
catch(IOException e){e.printStackTrace ();} 55.2UN
catch(Exception e){e.printStackTrace ();} PCaFG;}
} L`<#vi
~),%w*L
/y{fDCC
//读取保存的下载信息（文件指针位置） ?,riwDI 2
private void read_nPos() ;0kAm Vy
{ /f?;,CyI
try{ #FAW@6QG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6P>Y2xV:
int nCount = input.readInt(); (Q||5
nStartPos = new long[nCount]; ejR$N!LL
nEndPos = new long[nCount]; +-;v+{
for(int i=0;i<nStartPos.length;i++) qh6b;ae\x
{ r1IvA^X
nStartPos = input.readLong(); @BnK C&{
nEndPos = input.readLong(); NVkYm+J#
} 6<\dQ+~
input.close(); rMJ@oc
} |Tmug X7
catch(IOException e){e.printStackTrace ();} J&h59dm-
catch(Exception e){e.printStackTrace ();} Xlug{ Uh
} vgtAJp+p*
jbe:"Stw
9+m>|"F0
private void processErrorCode(int nErrorCode) _z%\53h
{ ?+=,t]`!m
System.err.println("Error Code : " + nErrorCode); <!G /&T
} rN#9p+t$
uy"i3xD6-
Y{e,I-"{
//停止文件下载 & ;5f/
public void siteStop() [V?HK_~
{ bt1bTo
bStop = true; L=Aj+
for(int i=0;i<nStartPos.length;i++) r*mYtS
fileSplitterFetch.splitterStop(); 2Q(ZW@0
:n~Mg{j3
vxPr)"Vvz
} tq}sedYhee
} X(d:!-_m *
//负责部分文件的抓取 /o$6"~t
**FileSplitterFetch.java xG edY*[`
*/ GBg
package NetFox; Iw?^
+ah4 K(+3
3C=QWw?
import java.io.*; dMjQV&
import java.net.*; t4;gY298
={o4lFe3v(
{c?{M.R
public class FileSplitterFetch extends Thread { ;dZZOocV1
7mi=Xa:U
.XK3o .ZhW
String sURL; //File URL MTE1\,
long nStartPos; //File Snippet Start Position R=R]0
long nEndPos; //File Snippet End Position U"@p3$2QW
int nThreadID; //Thread's ID En-=z`j G
boolean bDownOver = false; //Downing is over VrT-6r'Y
boolean bStop = false; //Stop identical (]mBAQ#hw
FileAccessI fileAccessI = null; //File Access interface JM0+-,dl[
Z[z" v
kd&~_=Q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #]i^L;u1A
{ jZ5ac=D&I
this.sURL = sURL; obbg#,
this.nStartPos = nStart; 2|exY>`w
this.nEndPos = nEnd; m|?1HCRXRI
nThreadID = id; V0,5c`H c
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {Gfsiz6
} 8KR17i1
9(=+OQ6
j1Sjw6}GCH
public void run() w"M!**bP
{ 4M>]0%3.D
while(nStartPos < nEndPos && !bStop) 'dQGb-<_<
{ 3\ )bg R:
It3@ Cd>
d\A7}_r*x
try{ ~Odclrs
URL url = new URL(sURL); &BKnJ{,H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U[yA`7Zs}
httpConnection.setRequestProperty("User-Agent","NetFox"); ~QE?GL
String sProperty = "bytes="+nStartPos+"-"; {Ho_U&<
httpConnection.setRequestProperty("RANGE",sProperty); x`wUi*G
Utility.log(sProperty); 7PfNPz<4+
Q-s5-&h(
h>xB"E|.
InputStream input = httpConnection.getInputStream(); z:O:g?A
//logResponseHead(httpConnection); b4KNIP7E
0lqh;/
l'!_km0{d
byte[] b = new byte[1024]; ZW;Re5?DJ
int nRead; M!VW/vdywL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <dS I"C<
{ ij?]fXf:)y
nStartPos += fileAccessI.write(b,0,nRead); QRdtr
//if(nThreadID == 1) _iqaKYT$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A5}N[|z
} ==KDr0|G
VL\Ah3+
Y?oeP^V'u
Utility.log("Thread " + nThreadID + " is over!"); 2I=4l
bDownOver = true; )h(=X&(d
//nPos = fileAccessI.write (b,0,nRead); 8-L -W[
} /^si(BuC^*
catch(Exception e){e.printStackTrace ();} 0yUn~'+(Sp
} [e|9%[.V
} {Aj=Rj@
JGhK8E
|9m*?7
//打印回应的头信息 ]REF1<)4z
public void logResponseHead(HttpURLConnection con) M6Ik'r"M
{ |D;I>O^"R
for(int i=1;;i++) L`w_Q2{sv
{ _lH:%E*
String header=con.getHeaderFieldKey(i); Fv^>^txh
if(header!=null) qssK0!-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^|h.B$_F,
Utility.log(header+" : "+con.getHeaderField(header)); n;.);
else 4Dd]:2|D
break; /GNm>NSK
} j3?@p5E(
} \$,;@H5I^
k_OzkEM9!
K9RRY,JB
public void splitterStop() )DQcf]I
{ (f"LD8MJ/
bStop = true; c/-'^+9
} V1,4M_Z
xiC.M6/
u3 4.
} K[-G2
)4GCL(&
IV`+B<3
/* .g_Kab3?L
**FileAccess.java eN TKX
*//文件访问(定位，写) py/#h$eY
package NetFox; ,G$<J0R1
import java.io.*; %x^U3"7
7X/B9Hee
0n?^I>j
public class FileAccessI implements Serializable{ *APTgXYR
SQG9m2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 qHYoQ.ke
RandomAccessFile oSavedFile; oHethk
long nPos; ) @f6
SUoUXh^!w
@w,O1Xwj
public FileAccessI() throws IOException (=Lx9-u
{ 40;4=
this("",0); <q4<3A
} }K 2fwE
|s !7U
W_]onq6
public FileAccessI(String sName,long nPos) throws IOException [Al}GM
{ U,\t2z
oSavedFile = new RandomAccessFile(sName,"rw"); |198A,^
this.nPos = nPos; ZlL]AD@
oSavedFile.seek(nPos); F^wm&:%{`
} D'_w *
0{47TX*YX
K3J,f2Cn$
public synchronized int write(byte[] b,int nStart,int nLen) ? C6tYd
{ *b(nX,e
int n = -1; T$Rf
try{ to] ~$~Q|>
oSavedFile.write(b,nStart,nLen); Ij7[2V]c
n = nLen; KA9v?_@{F
} D;oX*`
catch(IOException e) /Nd`eUn
{ JHsxaX;c
e.printStackTrace (); `+T"^{ Z
} K|wB0TiXP
:T/I%|;f
_Qf310oONS
return n; Y$eO:67;
} lMb&F[KJ7
-=4:qQEw
f]kG%JEK
} \hqjk:o
bR83N
*)qxrBc0
/* \ UiITP<
**SiteInfoBean.java rIAbr5CG
*/ ks(BS k4
package NetFox; {} Zqaf
zCFXQi
{bO O?pp
public class SiteInfoBean { >B+!fi'SS>
OP\m~1
7^]KQ2fF 8
private String sSiteURL; //Site's URL &]1gx#
private String sFilePath; //Saved File's Path 2Afg.-7EP
private String sFileName; //Saved File's Name zXv2plw(
private int nSplitter; //Count of Splited Downloading File ,-5|qko=
!s[[X5
iiTt{ab\Y
public SiteInfoBean() j4]y(AA
{//nSplitter的缺省值为5 Q;eY]l8
//default value of nSplitter is 5 1c*XmMB
this("","","",5); l[b`4
} t'bhA20Z\
;^|:*
2X@"#wIg
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Na$[nv8qh
{ {*K7P>&
sSiteURL= sURL; C;XhnqWv+l
sFilePath = sPath; f2Z(hYH~
sFileName = sName; yuq2)
this.nSplitter = nSpiltter; k[5:]5lp+
s73'h
em?Q4t
} L}pj+xB
=nE^zY2m%
kuW^_BROJ
public String getSSiteURL() IOOK[g.?h
{ T8>aU
return sSiteURL; rE9Nt9}
} S0!w]Ku
\JIyJ8FleC
U'0e<IcY
public void setSSiteURL(String value) IQQ QB
{ $9?<mP2-*
sSiteURL = value; hf< [$B
} @5*$yi 'Cp
dc,qQM
b-HELS`nX
public String getSFilePath() C,VvbB
{ E5g|*M.+f
return sFilePath; &ZI-#(P
} zAH6SaI$
b r\_
IRT0
public void setSFilePath(String value) n|eM}ymF+
{ b>L?0p$ej
sFilePath = value; p|Nh:4iN
} tYMPqP,1.
"43F.!P
V$3`y=8
public String getSFileName() [Lq9lw&
{ ;={3H_{3
return sFileName; (0^ZZe`#j
} )_SpY\J
>- U+o.o
{fS~G2@1
public void setSFileName(String value) {_~vf
{ ayQ2#9X}
sFileName = value; 'C) v?!19
} DIx.a^LR
J7+[+Y
=TJ9Gr/R&:
public int getNSplitter() hr3<vWAD
{ puox^
return nSplitter; $) m$c5!
} '+7"dHLC;
Ih)4.lLcKn
z8cefD9F
public void setNSplitter(int nCount) 40}7O<9*
{ [I`:%y
nSplitter = nCount; -9(pOwN |m
} kbZpi`w
} .Ky)Co
Lwn
"D'"uMS`H
/* 61](a;Di
**Utility.java zJo?,c
*/ F(|XJN
package NetFox; H:cAORLB
%a']TX
yf/i)
public class Utility { U<<XeSp
8&3KVd`
!wTrWD!
public Utility() zZ;V9KM>v
{ &pW2R}
lN*beOj
7QRkXs
} fGoJP[ae
ox5WboL
//线程睡眠 Q hdG(`PY~
public static void sleep(int nSecond) (C0Wty
{ Z{x)v5yh2V
try{ m"!Q5[
Thread.sleep(nSecond); c2-oFLNP=
} Y=t?"E
catch(Exception e) IZs&7
{ J vq)%t8q>
e.printStackTrace (); q7<=1r+
} JJ9R, 8n6
} nf1O8FwRb
wV-9T*QrM
//日志 <!F".9c@A
public static void log(String sMsg) 8*Ty`G&v
{ vIf-TQw
System.err.println(sMsg); !,]2.:{0z
} c#TV2@
U9jdb9 |
{.ypZ8JU
public static void log(int sMsg) (__$YQ-
{ {vdY(
System.err.println(sMsg); \&47u1B
} $gZiW8
} i|m8#*Hd
_qk yU)z
ld3H"p rR
/* EvH/d4V;
**TestMethod.java Vh>|F}%E
*/ uU%Z%O
package NetFox; QseV\;z
ZG-#YF.1
GL~ Wnt
public class TestMethod { -fp/3-
o`G6!
-ijzo%&qA
public TestMethod() cbl>:ev1h
{ ///xx/weblogic60b2_win.exe _D$1CaAYo
try{ Kg`P@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yzZzaYv "/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0!oqP1
SiteFileFetch fileFetch = new SiteFileFetch(bean); [w!T
fileFetch.start(); p=3t!3
} HJBGxyw
catch(Exception e){e.printStackTrace ();} N3N~z1x0h
gu:vf/
F{^\vFp
} Y`d@4*FN$
'#SZ|Rr6tX
JI cm$
public static void main(String[] args) Jg)( F|>o
{ Y=?{TX=6<[
new TestMethod(); mE_%
} h=\1ZQKC)
} I L,lXB<
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