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)); =a+ } 6
} 2/A*\
for(int i=0;i<nEndPos.length-1;i++) 9* 3;v;F
{ =~W=}
nEndPos = nStartPos[i+1]; ci2Z_JA+
} ^C~R)M:C
nEndPos[nEndPos.length-1] = nFileLength; FAc^[~E
} !wEe<],
} hW!n"qU
a @3s71
4bw4!z9G
//启动子线程 nJYIkfdA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; * Wp?0CP
for(int i=0;i<nStartPos.length;i++) \I}EWI
{ ^ZS!1%1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @x!+_z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,H.5TQ#
nStartPos,nEndPos,i); h0dZr-c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -(lP8Y~gFY
fileSplitterFetch.start(); kmu`sk"
} 9I<~t@q5e@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }!Pty25j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); umnQ$y 0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =w`uZ;l$Q
nEndPos = " + nFileLength); w 2U302TZ
// fileSplitterFetch[nPos.length-1].start(); n`w]?bL
Pe\Obd8d
2T?Y
//等待子线程结束 T fIOS]
//int count = 0; [Pjitw/?
//是否结束while循环 c1a$J`
boolean breakWhile = false; a-FI`Dv
-nHkO&&R
gzKMGL?%?
while(!bStop) S!gzmkGcj
{ [iO8R-N8d
write_nPos(); eGpKoq7a
Utility.sleep(500); #+U1QOsz
breakWhile = true; 1$C?+H
zv/dj04>
?fC9)s
for(int i=0;i<nStartPos.length;i++) d8 Jf3Mo
{ Wuk8&P3
if(!fileSplitterFetch.bDownOver) 0m> 8
{ ]i0=3H2
breakWhile = false; U~?mW,iRL
break; 6=,zkU*i^
} zd!%7 UP
} xb0,dZb
if(breakWhile) #%E^cGfY
break; !j%
(=c,b9cb
gzat!>*
//count++; ,#GB
//if(count>4) "zXrfn
// siteStop(); UmGKj9u
} p"jze3mF
j%bC9UkE3
5cU:wc
System.err.println("文件下载结束！"); Rcw[`q3/
} 's5rl
catch(Exception e){e.printStackTrace ();} ~QPTs1Vk8
} BB69U
gdqBT]j
]yqE6Lf9
//获得文件长度 EH M59s|B
public long getFileSize() }#4Ek8nFR
{ &?1^/]'"r
int nFileLength = -1; <~w3[i=
try{ ln8NcAEx
URL url = new URL(siteInfoBean.getSSiteURL()); P*|=Z>%[0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5=#d#dDc
httpConnection.setRequestProperty("User-Agent","NetFox"); emrA!<w!W
p-EU"O
VMJaL}J]
int responseCode=httpConnection.getResponseCode(); k%O3\q
if(responseCode>=400) ]'Ho)Q
{ _$D!"z7i
processErrorCode(responseCode); h.ftl2>
return -2; //-2 represent access is error qAbmQ{|w
} fXl2i]L(^B
]sVWQj
I"lzOD; eI
String sHeader; 8{i}^.p
?r8hl.Z>
$Q'z9ghEg
for(int i=1;;i++) f$-n%7
{ 55$';gh,9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sb8bCEm-\
//Utility.log(in.readLine()); 7_)38
sHeader=httpConnection.getHeaderFieldKey(i); _TsN%)m
if(sHeader!=null) 1t?OD_d!8
{ A9K$:mL<2
if(sHeader.equals("Content-Length")) cRbA+0m>
{ 39P55B/o%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >C6S2ISSz
break; 2@z.ory.
} )b2O!p
} tAJ}36aG
else Q#qfuwz
break; u'_}4qhCC;
} 2?Jw0Wq5D
} .S/zxf~h
catch(IOException e){e.printStackTrace ();} C3f\E: D)
catch(Exception e){e.printStackTrace ();} 6hYz^}2g
w4TQ4 Y
'2<r{
Utility.log(nFileLength); NqOX);'L0
(6a<{
?fq!BV
return nFileLength; +By'6?22
} <)(W7#Ks
HKT, 5
oS9Od8
//保存下载信息（文件指针位置） ~@xPoD&
private void write_nPos() BQg3+w:>
{ &V(6N%A^U
try{ `Z5dRLrd
output = new DataOutputStream(new FileOutputStream(tmpFile)); mR XRuK
output.writeInt(nStartPos.length); x`@`y7(
for(int i=0;i<nStartPos.length;i++) Ny$3$5/
{ GQ@mQ=i
// output.writeLong(nPos); /Qr`au
output.writeLong(fileSplitterFetch.nStartPos); I{[Z
output.writeLong(fileSplitterFetch.nEndPos); .43cI(
} Gbclu.4
output.close(); Vym0|cW
} w"dKOdY
catch(IOException e){e.printStackTrace ();} ~XuV:K3
catch(Exception e){e.printStackTrace ();} YCxwIzIR
} M_ %-A
Khc^q*|C)
0^uUt-
//读取保存的下载信息（文件指针位置） ~:f..|JM
private void read_nPos() aHpZhR|f$
{ ZBY2,%nAo
try{ +>!nqp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \$Wpt#V
int nCount = input.readInt(); u?dPCgs;h
nStartPos = new long[nCount]; {xov8M
nEndPos = new long[nCount]; 3Xd:LDZ{
for(int i=0;i<nStartPos.length;i++) 5toa@#Bc%
{ AL3iNkEa
nStartPos = input.readLong(); t;h`nH[
nEndPos = input.readLong(); z5M6
} {en'8kS
input.close(); HSROgBNI:
} a <?~1pWtc
catch(IOException e){e.printStackTrace ();} 5~IdWwG*w
catch(Exception e){e.printStackTrace ();} sr&W+4T
} z rSPa\M
I%a-5f$0
fDqT7}L
private void processErrorCode(int nErrorCode) x:!s+q` s
{ bl^Ihza
System.err.println("Error Code : " + nErrorCode); .yXqa"p
} -q{N1?tcy
g:JSy
'&#gs P9
//停止文件下载 SKnYeT
public void siteStop() 23L>)Q
{ O |P<s+
bStop = true; +8N6tw/&
for(int i=0;i<nStartPos.length;i++) 6Nn+7z<*&z
fileSplitterFetch.splitterStop(); 8t*sp-cy|
At=d//5FFP
N=2T~M 1
} C,l,fT
} Qm[s"pM
//负责部分文件的抓取 hd9HM5{p
**FileSplitterFetch.java (M$>*O3SR
*/ 4l%W]'
package NetFox; Hh=fv~X
|>]@w\]
Wmcd{MOS
import java.io.*; EC,`t*<
import java.net.*; MU a[}?
QE[<Y3M
.aY$-Y<
public class FileSplitterFetch extends Thread { !KK`+ 9/
c5WMN.z
pl&nr7\
String sURL; //File URL ur'<8pDb$
long nStartPos; //File Snippet Start Position Kh$"5dy
long nEndPos; //File Snippet End Position #Iz)Mu
int nThreadID; //Thread's ID J}xM+l7uY
boolean bDownOver = false; //Downing is over lRg?||1ik
boolean bStop = false; //Stop identical eZT8gKbjJ)
FileAccessI fileAccessI = null; //File Access interface 1a{3k#}
&Z]}rn
Z@+nkTJ9&t
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /v5A)A$7
{ 8ex;g^e
this.sURL = sURL; NC-K`)
this.nStartPos = nStart; _`\!+qGq
this.nEndPos = nEnd; YWH>tt9
nThreadID = id; oxc;DfJ_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 PJN9[Y{^3
} B1nm?E 0i
C&w0HoF
&F~d~;G"q
public void run() o(jLirnk
{ ZJBb%d1;
while(nStartPos < nEndPos && !bStop) tjXg
{ iVZ}+Ct<"
xE?KJ
zs#-E_^%M
try{ e3;D1@
URL url = new URL(sURL); \Yr*x7!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d%'#-w'
httpConnection.setRequestProperty("User-Agent","NetFox"); B0Wf$ s^7t
String sProperty = "bytes="+nStartPos+"-"; v~L\[&|_
httpConnection.setRequestProperty("RANGE",sProperty); FJ~d&L\l
Utility.log(sProperty); /&#y-D_
I{(!h90
lgU!D |v
InputStream input = httpConnection.getInputStream(); BVb^xL
//logResponseHead(httpConnection); LsERcjwwK
^ l]!'"
/)_4QSz7
byte[] b = new byte[1024]; 08nh y[
int nRead; Wds>'zzS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c 1F^Gj!8
{ K& ^qn&
nStartPos += fileAccessI.write(b,0,nRead); lUEbxN
//if(nThreadID == 1) Nz`8)Le
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "crR{OjE"
} T/P\j0hR
I &iyj99n
$oQOOa@;i)
Utility.log("Thread " + nThreadID + " is over!"); J2VPOn
bDownOver = true; ;`7~Q
//nPos = fileAccessI.write (b,0,nRead); h76j|1gI
} 9t\14tVwx
catch(Exception e){e.printStackTrace ();} %MHL@Nn>e
} La1:WYt
} |cY HH$
%;:![?M
W$hCI)m(
//打印回应的头信息 *P*~CHx>
public void logResponseHead(HttpURLConnection con) :[n~(~7?
{ ,nteIR'??
for(int i=1;;i++) u?72]?SM
{ K _VIk'RB
String header=con.getHeaderFieldKey(i); ^R@)CIQ
if(header!=null) 5 [~HL_u;,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (]'wQ4iQ
Utility.log(header+" : "+con.getHeaderField(header)); tB>!1}v
else z]8Mv(eL
break; s|<n7 =J
} Q;3`T7
} x!GDS>
g3kbsi7_:
Gpxp8[ {
public void splitterStop() Q"FN"uQ}x
{ ivo><"Y(r
bStop = true; M8WjqTq
} S,:!H@~B
1w7tRw
}kmAUaa,Z
} cF15Mm2
7/<~s]D[%
TzaeE
/* =A6*;T"W
**FileAccess.java kQ\ $0=6N9
*//文件访问(定位，写) /W,hOv
package NetFox; 0j!<eN=
import java.io.*; _WWC8?6U
3:jxr
xFp$JN
public class FileAccessI implements Serializable{ zy$jTqDH
m=9b/Nr4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RM_%u=jC
RandomAccessFile oSavedFile; ?+hEs =Xs
long nPos; |k6+- 1~_
Iz+%wAZ|B6
O/#3QK
public FileAccessI() throws IOException _=I1
{ 'hr_g* i
this("",0); M%ecWr!tj
} !8UIyw
m^L!_~
:(US um
public FileAccessI(String sName,long nPos) throws IOException WZ?>F
{ Ne<S_u2nT
oSavedFile = new RandomAccessFile(sName,"rw"); ~2rQ80_
this.nPos = nPos; K9xvog
oSavedFile.seek(nPos); #>aq'47j
} +g?uvXC&
> .NLmzUX
"G>d8GbIh
public synchronized int write(byte[] b,int nStart,int nLen) n! 5(Z5=
{ A-4;$ QSm
int n = -1; +&u/R')?6r
try{ afX|R
oSavedFile.write(b,nStart,nLen); ((]i}s0S
n = nLen; [(*Eg!?W=
} Y(6evo&IR
catch(IOException e) E}9wzPs
{ &Pme4IHtm
e.printStackTrace (); ~vDa2D<9%
} {c)\}s(}F
V $I8iVGL
%( 7##f_
return n; P.Bwfa
} | I:@:
!%65YTxY-
LI.WcI3uS
} ShC$ue?Q
':_9o5I
ktfm
/* .:&`PaMt
**SiteInfoBean.java mTu>S
*/ 9+9g(6
package NetFox; yOz6a :r
V. i{IW
&X:;B'
public class SiteInfoBean { =M-=94
F&!vtlV)
fWJpy#/^*K
private String sSiteURL; //Site's URL 2R,} j@
private String sFilePath; //Saved File's Path >(P(!^[f
private String sFileName; //Saved File's Name U:8]G
private int nSplitter; //Count of Splited Downloading File z0LspRaz
vW eg1
=cV|o]
public SiteInfoBean() Z4Q]By:/L
{//nSplitter的缺省值为5 %2dzx[s
//default value of nSplitter is 5 u3qxG3
this("","","",5); ;8PO}{rD
} giu{,gS0?M
E`_T_O=P
?l%4 P5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4F.,Y3
{ P`@Rt
sSiteURL= sURL; ]:LlOv$
sFilePath = sPath; U%bm{oVn
sFileName = sName; z<9C-
this.nSplitter = nSpiltter; !y XGAg,
D*2*FDGI
s i2@k
} 3);P!W4>
Mrgj*|
$=diG
public String getSSiteURL() hO[_ _j8
{ |oU I2<"
return sSiteURL; kiJ=C2'&
} Hre&a!U
<o|fH~?X
c6 &k?Puy
public void setSSiteURL(String value) <vWP_yy
{ v3cMPN
sSiteURL = value; KwHN c\\
} kCD]&
n[e C
ynM:]*~K
public String getSFilePath() ./;uhj
{ 94&t0j_
return sFilePath; .F$}a%
} F8<G9#%s\
ByP<-Deh
!0hyp |F:>
public void setSFilePath(String value) \E,2VM@6
{ [ x+-N7
sFilePath = value; y'`7zJ
} .9e5@@VR
]wDqdD y7S
qdZ ^D
public String getSFileName() eY#^vB
{ wipl5O@L
return sFileName; X<IW5*
} oS$7k3s fj
40MKf/9
\:Tq0|]Px
public void setSFileName(String value) 9d|8c > I
{ 8/j|=Q,5
sFileName = value; ` Ny(S2
} #*pB"L
`},:dDHI
:k?`gm$
public int getNSplitter() ;/kd.Q
{ B|a<=~
return nSplitter; VD&wO'U
} @yb'h`f]
M2ex 3m
G{6@]72
public void setNSplitter(int nCount) 8D`+3
{ Xj+_"0 #
nSplitter = nCount; I2HV{1(i
} i/-IjgM"-
} Epp>L.?r
.S|T{DMQ[
j;uUM6
/* `q]' ^EzJ
**Utility.java @mZK[*Ak<*
*/ nI?*[y}
package NetFox; @d{}M)6\!
$!. [R}
r4[=pfe25
public class Utility { 1lIs jBo g
IY6Ll6OK
2~hdJ/
public Utility() wN'S+4
{ n:40T1:q
,=CipL9]
_+P*XY5
} 0 N7I:vJ
p/_W*0/i
//线程睡眠 A@|Z^T:
public static void sleep(int nSecond) gYN;Fu-9Z
{ XGR63hXND
try{ M:OZWYQ
Thread.sleep(nSecond); 5P #._Em
} T_2'=7
catch(Exception e) yn ofDGAf
{ uY)4y0
e.printStackTrace (); 7Fpa%N/WL
} EwG+' nlE
} ?MSZO]Q4+
[V_mF
//日志 ha|2u(4
public static void log(String sMsg) X~m57bj
{ :CM-I_6
System.err.println(sMsg); 9$v\D3<Z
} *-]k([wV
&u|t{C#0
=.S2gO >
public static void log(int sMsg) 2u_=i$xW
{ gYbvCs8O!
System.err.println(sMsg); wT+60X'
} YhglL!pC
} l2W+VBn6
}` `oojz
OO/>}? ob
/* zx"EAF{
**TestMethod.java Bi fI.2|
*/ D_<B^3w)
package NetFox; JfJ ln[
yD3vq}U!
}mp`!7?>O
public class TestMethod { sCy.i/y
"Ke_dM
=>Ae]mi7
public TestMethod() Kc r)W
{ ///xx/weblogic60b2_win.exe ;;UsHhbhI
try{ IuPDr %
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~hk!N!J\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o+OX^F0
SiteFileFetch fileFetch = new SiteFileFetch(bean); W!8$:Ih_Z
fileFetch.start(); UE_>@_T
} BSy4 d>
catch(Exception e){e.printStackTrace ();} 4V@0L
GPAC0K^p
vr47PM2al
} (.oDxs()I
FLPN#1
myXGMN$i
public static void main(String[] args) *URY8a`bO
{ eWYet2!Q
new TestMethod(); `mAYK)N
} .-s!} P"
} >oy%qLHe~t
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