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$;#=WAY
} NJ];Ck
for(int i=0;i<nEndPos.length-1;i++) f.X<Mo
{ e/*T,ZJ
nEndPos = nStartPos[i+1]; pipO,n
} +D&aE$<
nEndPos[nEndPos.length-1] = nFileLength; [\ALT8vC?m
} E%tGwbi7
} *~H\#N|x
W2 p&LP
b0n " J`
//启动子线程 %M KZ':m
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Wd78 bu|
for(int i=0;i<nStartPos.length;i++) !T3b]0z
{ c^a Dr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @GrQ/F7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $CgR~D2G
nStartPos,nEndPos,i); i<ug("/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <f+9wuZ
fileSplitterFetch.start(); WD${f#]N
} hNWZ1r~_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CpG]g>]L&[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =MCQNyf+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;kv/(veQ1<
nEndPos = " + nFileLength); [n!5!/g>j
// fileSplitterFetch[nPos.length-1].start(); gdKn!; ,w#
[Kc"L+H\
QW[ gDc
//等待子线程结束 I&lb5'6D
//int count = 0; b!hs|emo;
//是否结束while循环 {6, l#z
boolean breakWhile = false; Aq~}<qkIF+
/6@~XO)w
[(65^Zl`
while(!bStop) zv>3Tc0R
{ 'Bc{N^
write_nPos(); L2GUrf
Utility.sleep(500); ln~;Osb
breakWhile = true; M}cgVMW
5:r*em
A\IQM^i
for(int i=0;i<nStartPos.length;i++) IA$)E
{ ^}>Ie03m50
if(!fileSplitterFetch.bDownOver) v0|[w2Q2
{ Dx1w I
breakWhile = false; F )|0U~
break; (^)" qsB
} B<}0r4T}
} ~8#Ku,vEy
if(breakWhile) _/(7:
break; VP\'p1a
vSf ?o\O
fVJsVZ"6v`
//count++; zVL"$ )
//if(count>4) `Fn6*_n
// siteStop(); ja1WI
} qT}AY.O%^
g82_KUkB
Yc]
System.err.println("文件下载结束！"); (}jYi*B
} KOqp@K$
catch(Exception e){e.printStackTrace ();} W:z?w2{VI(
} ]u\K}n6[q
q[rBu9
`~ ,
//获得文件长度 |1z?#@BH
public long getFileSize() iJH;OV;P
{ H)u<$y!8
int nFileLength = -1; Frxim
try{ >^\}"dEvr
URL url = new URL(siteInfoBean.getSSiteURL()); Z6Kw'3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E/[<} ./
httpConnection.setRequestProperty("User-Agent","NetFox"); E?@batIrf
KTzkJx
|#x]FNg
int responseCode=httpConnection.getResponseCode(); XX])B%*
if(responseCode>=400) =^L?Sgg
{ PX%Y$`
processErrorCode(responseCode); 4IEF{"c_8
return -2; //-2 represent access is error D%k`udz<
} &N^^[ uG
]EhU8bZ
(w+dB8)X
String sHeader; kCoTz"Z-
N4z(2.
"h>B`S
for(int i=1;;i++) `VB]4i}u
{ =5PNH2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); f-M9OI
//Utility.log(in.readLine()); WOgPhJ
sHeader=httpConnection.getHeaderFieldKey(i); 7G^`'oZ
if(sHeader!=null) c(tX761qz
{ xbeVqP
if(sHeader.equals("Content-Length")) B"9/+Yj
{ 5qx,b&^w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K.{:H4_
break; {Al}a`da
} pMfP3G7V
} S9'8rn!_
else e?"XMY
break; X=Th
} 'Itsu~fza
} 6,D)o/_
catch(IOException e){e.printStackTrace ();} `!t+sX-n
catch(Exception e){e.printStackTrace ();} =@UgCu>=
O_n) 2t(c?
acXB vs
Utility.log(nFileLength); `QIYnokL
w&F/P]1
H$j`75#u?-
return nFileLength; ) C?emTih
} @\_l%/z{
GdxMHnn=
.^Z^L F
//保存下载信息（文件指针位置） .gPXW=r
private void write_nPos() XKTX~:
{ 0i4X,oHjG
try{ ?'I[[KuG
output = new DataOutputStream(new FileOutputStream(tmpFile)); i5QG_^X&
output.writeInt(nStartPos.length); \vU1*:3
for(int i=0;i<nStartPos.length;i++) G31??L:<
{ _ zh>q4M
// output.writeLong(nPos); .%iJin"
output.writeLong(fileSplitterFetch.nStartPos); 4IW7^Pq`P
output.writeLong(fileSplitterFetch.nEndPos); e!:/enQo
} [^U#ic>cT
output.close(); 3O W)%
} (zm5 4 Vm
catch(IOException e){e.printStackTrace ();} >*5+{~k~4
catch(Exception e){e.printStackTrace ();} RH+'"f
} b.<>CG'
ns{BU->f
) ag8]
//读取保存的下载信息（文件指针位置） pX nY=
private void read_nPos() #DL( %=:
{ oZY2K3J)
try{ 0^27grU>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Xg](V.B6
int nCount = input.readInt(); RnA>oKc
nStartPos = new long[nCount]; j\ dY
nEndPos = new long[nCount]; ,s?7EHtC
for(int i=0;i<nStartPos.length;i++) LHt{y3l]
{ ]Gm$0uS
nStartPos = input.readLong(); ~sI$xX!
nEndPos = input.readLong(); ]lKQwpX3
} *TjolE~o
input.close(); T2nbU6H
} 7H1 ii
catch(IOException e){e.printStackTrace ();} 5g{L -8XwI
catch(Exception e){e.printStackTrace ();} `3v!i
} I^5T9}>Q
RawK9K_1
ae)0Yu`*G7
private void processErrorCode(int nErrorCode) ; U)a)l'y
{ 1lxsj{>U
System.err.println("Error Code : " + nErrorCode); tPT\uD#t
} GQNs:oRJ'
^Ms)T3dM
m]1=o7
//停止文件下载 S<hj6A
public void siteStop() rb/m;8v>
{ ]m#.MZe
bStop = true; 4)o_gm~6c4
for(int i=0;i<nStartPos.length;i++) :?Xd&u0){
fileSplitterFetch.splitterStop(); 5 W<\J
x<0-'EF/S
G%a8'3d,
} kH!I&4d&
} hLVS}HE2
//负责部分文件的抓取 iXN7+QO)
**FileSplitterFetch.java [w%MECTe
*/ 8-N8v *0
package NetFox; RaKfYLw
Q9lw~"
$II[b-X?S
import java.io.*; /\%K7\
import java.net.*; Q]';1#J\
H$^b.5K
Su<Ggv"
public class FileSplitterFetch extends Thread { +TzF*Np
|P_\l,f8`
xZ51iD$
String sURL; //File URL [e2sUO0~r
long nStartPos; //File Snippet Start Position ;CU<\
long nEndPos; //File Snippet End Position *0 ;DCUv
int nThreadID; //Thread's ID -%&_LE9ZtS
boolean bDownOver = false; //Downing is over -fl?G%:(!0
boolean bStop = false; //Stop identical FtUOgL)|
FileAccessI fileAccessI = null; //File Access interface &S}i)Nu6J
TzXivE@mm
U&fOsx?"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U/ncD F%C
{ cxTP4\T\E
this.sURL = sURL; rz]0i@ehv'
this.nStartPos = nStart; &^ sgR$m
this.nEndPos = nEnd; 't$(Ruw
nThreadID = id; IT,TSs/Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /t-m/&>
} +$MNG
`U4R% qhWA
Bi"7FF(z
public void run() tylMJ$ 9*.
{ g)*[W>M
while(nStartPos < nEndPos && !bStop) f-9&n4=H
{ `;7^@k
:X>%6Xj?RV
~q]+\qty4
try{ mPNT*pAO
URL url = new URL(sURL); f>)k<-<yj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6V=69}
httpConnection.setRequestProperty("User-Agent","NetFox"); Q 'R@'W9
String sProperty = "bytes="+nStartPos+"-"; :t\pi.uWt
httpConnection.setRequestProperty("RANGE",sProperty); K~A$>0c
Utility.log(sProperty); "5mdq-h(
c9\jELO
zcGeXX}V?
InputStream input = httpConnection.getInputStream(); )%q]?@kB
//logResponseHead(httpConnection); n'D1s:W^B
>9{Gdq[gyr
1FU(j*~:
byte[] b = new byte[1024]; 0>Y3>vwSl
int nRead; 7Op6>i
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uBLI!N-G
{ nB?$W4
nStartPos += fileAccessI.write(b,0,nRead); Z~^)B8
//if(nThreadID == 1) sQrP,:=r#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D 8^wR{-;J
} G>{Bij44
xU#f>@v!
7/lXy3B4
Utility.log("Thread " + nThreadID + " is over!"); T:aYv;#0
bDownOver = true; c&.>SR')
//nPos = fileAccessI.write (b,0,nRead); V`Z-m-V~1
} *.wX9g9\
catch(Exception e){e.printStackTrace ();} K &m`1f
} umrfA
} Bk&ry)`gD
<Q'J=;vV
S[rz=[7{
//打印回应的头信息 3z9}cOFq]z
public void logResponseHead(HttpURLConnection con) )CQ'kHT<e
{ [psW+3{bG
for(int i=1;;i++) bX%9'O[-
{ 7A|n*'[T>
String header=con.getHeaderFieldKey(i); PSz|I8 c
if(header!=null) fOEw]B#@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); T+7O+X#
Utility.log(header+" : "+con.getHeaderField(header)); won;tO]\;@
else ~=~|@K
break; Sw<@u+Z;%
} ftB-gItV
} gT$`a
mGZ^K,)&OR
/k3v\Jq{
public void splitterStop() M<oIo036
{ ~G.'pyW
bStop = true; ohqi4Y!j/~
} '`Eb].s*
_NQMi4 V(
E}K6Op;=v5
} aMQfg51W:
t<5$85Y~
hnag<=
/* LIYj__4=|
**FileAccess.java r9<OB`)3+
*//文件访问(定位，写) !, Y1FC
package NetFox; '{+5+ J
import java.io.*; m[6?v;w
Zq7Y('=`t@
vZ[wr@)
public class FileAccessI implements Serializable{ t'Zq>y;yg
U_ELeW5@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ygoA/*s
RandomAccessFile oSavedFile; 4lMf'V7*l
long nPos; ^]}+s(
JGl0 (i*|
D?ojxHe
public FileAccessI() throws IOException ?7>G\0G
{ -\C;2&(
this("",0); -?L~\WJAL
} +?r,Nn
#[$^M:X.
v4c*6(m
public FileAccessI(String sName,long nPos) throws IOException o9I=zAGjy
{ Yxik.S+G
oSavedFile = new RandomAccessFile(sName,"rw"); 2wR?ON=Q
this.nPos = nPos; vz'/]E
oSavedFile.seek(nPos); LYY3*d
} MYyV{W*T>
\\w<.\Yh
GH ]c
public synchronized int write(byte[] b,int nStart,int nLen) [t#xX59
{ 8NCu;s
int n = -1; !R@v\Eu
try{ ejs_ ?
oSavedFile.write(b,nStart,nLen); %l{0z<
n = nLen; =^a Ngq
} (lPiv+'n
catch(IOException e) ;ED` 7
{ JmlMfMpXMs
e.printStackTrace (); /j%(Z/RM
} 9R$0[HbI3
hO8~Rg
haNi[|
return n; 2>`m1q:
} cg`bbZ
h"O4r8G}
>~_oSC)E
} \N3A2L)l
\PU7,*2
Q`= ,&;T>
/* n:dnBwY
**SiteInfoBean.java f%#q}vK-
*/ 'P'f`;'_DC
package NetFox; 2Kg-ZDK8
p;nRxi7'
EhWYFQ
public class SiteInfoBean { \\U,|}L .
faTp|T`nY
Tj(DdR#w
private String sSiteURL; //Site's URL _z6_mmMp
private String sFilePath; //Saved File's Path (AIgW
private String sFileName; //Saved File's Name W"3YA+qpI
private int nSplitter; //Count of Splited Downloading File u7>{#]
k`aHG8S\
RX])#=Cs
public SiteInfoBean() PvHX#wJ
{//nSplitter的缺省值为5 I='6>+P
//default value of nSplitter is 5 UO~Xzx!e
this("","","",5); /9QC$Z):<
} /&>vhpZ}
X0FTD':f
8%\0v?a5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p)&Yr
{ 1@}s:
sSiteURL= sURL; *'l|ws
sFilePath = sPath; f3;.+hJ])
sFileName = sName; bz'#YM
this.nSplitter = nSpiltter; *@+E82D
Z@1vJH6IbA
PS:"mP7n
} ",,W1]"%
6B8gMO
&m5FYm\
public String getSSiteURL() ^}Wk
{ z79c30y]"
return sSiteURL; j3t,Cx
} _48@o^{
YP4lizs.
hBRcI0R
public void setSSiteURL(String value) fk5$z0/
{ G4<M@ET
sSiteURL = value; W ])Lc3X
} l$:?82{
qmy3pnL
4Pv Pp{Y
public String getSFilePath() gcI?)F
{ /:GeXDJw
return sFilePath; jt?DogYx
} bmP2nD6
0wE)1w<C~
O'.sK pXe
public void setSFilePath(String value) qGkD] L
{ U32&"&";c
sFilePath = value; wSPwa,)7s
} <FofRFaS
uXuA4o$t-
'UFPQ
public String getSFileName() a<CJ#B2K
{ NK!#K>AO
return sFileName; /6@$^paB
} H"b}lf
>c30kpGg
;!:@3c
public void setSFileName(String value) q]\GBRp
{ [}Z!hq
sFileName = value; \Y$@$)
} D:=Q)Uh0I
^&!iqK2o
/cC4K\M
public int getNSplitter() H[J5A2b
{ qA>C<NL
return nSplitter; ?'/#Gt`
} M{)|9F
Dd'4W
'z$!9ufY,
public void setNSplitter(int nCount) LUKt!I0l
{ L43]0k
nSplitter = nCount; q]rqFP0C
} e13' dCG
} 78h!D[6
%pUA$oUt
z/P^Bx]r
/* @3_."-d
**Utility.java ;y]BXW&l&
*/ =2OLyZDI
package NetFox; )u>/:
Lg2z `uv
$*qQ/hi
public class Utility { <!a%GI
DTN)#GCtF
f\X7h6k8{
public Utility() ]&_z@Z.i
{ e3=-7FU
20`QA u)'
Lgrpy
} a_(fqoW
^X|Bzz)
//线程睡眠 @$R^-_m
public static void sleep(int nSecond) \rSofn#c
{ p"|0PlW
try{ ?F^O7\rw
Thread.sleep(nSecond); $0,lE+7*
} ~vV+)KI
catch(Exception e) /7&WFCc)(
{ "VgPaz#
e.printStackTrace (); 1qE*M7_:E>
} \:Z8"~G
} owe6ge7m
V*%Lc9<d
//日志 4YyVh.x
public static void log(String sMsg) W0\ n?$ZC~
{ I!u fw\[
System.err.println(sMsg); bF c %
} ve*m\DU
WVdF/H
@XN*H- |
public static void log(int sMsg) (dHil#l
{ 4Ixu%
System.err.println(sMsg); h:Hpz
} 4=C7V,a
} !~-@p?kW/
4%>2>5
v O@7o
/* 1JY3c M
**TestMethod.java Z ItS(oJ.
*/ -m_H]<lWZ
package NetFox; j%Wip j;c
I9hZ&ed16
zc&i 4K
public class TestMethod { u$ a7
';KZ.D
!Nx'4N`&l
public TestMethod() I`S?2i2H
{ ///xx/weblogic60b2_win.exe sG:tyvln
try{ *ulkqpO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >{.|Ng4K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Fh~ pB>t
SiteFileFetch fileFetch = new SiteFileFetch(bean); L%31>)8
fileFetch.start(); 6rh^?B
} H57wzG{xG
catch(Exception e){e.printStackTrace ();} `8b4P>';O'
n|) JhXQ
p#>d1R1&
} MxLi'R=
s/0~!0
&e;GoJ
public static void main(String[] args) 8=WX`*-uH
{ UsnIx54D3
new TestMethod(); de,4Ms!%
} fea4Ul{ib
} M:R|hR{=*
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