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)); H&"_}
} s0x@ u
for(int i=0;i<nEndPos.length-1;i++) kfH9Y%bOy
{ ?z*W8b]'
nEndPos = nStartPos[i+1]; j 8~Gv=(h
} }])GQ@
nEndPos[nEndPos.length-1] = nFileLength; O~7p^i}
} <FMuWHY
} ,C5@P+A
"j*fVn
0Og/47dO.2
//启动子线程 G7Edi;y/{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z&2 &wD
for(int i=0;i<nStartPos.length;i++) t[L2'J.5
{ UMnR=~.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iPRJA{$b_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]9!Gg
nStartPos,nEndPos,i); <m|FccvQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Vs2v j
fileSplitterFetch.start(); krnvFZRTQ
} <v1_F;{n
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EBN]>zz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); BV_a-\Sa=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #d7)$ub
nEndPos = " + nFileLength); zIX}[l4EW~
// fileSplitterFetch[nPos.length-1].start(); SLbavP#G
|V*e2w
P,s)2s'nZ
//等待子线程结束 6|>"0[4S
//int count = 0; >d1aE)?
//是否结束while循环 _dH[STT
boolean breakWhile = false; |\yDgs%EGy
[kU[}FT
fb;hf:B:
while(!bStop) FQv02V+&<
{ ;NvhL|R
write_nPos(); C/grrw
Utility.sleep(500); \, X?K
breakWhile = true; OP\^c
O~c+$(
~a0d.dU
for(int i=0;i<nStartPos.length;i++) r;5 AY
{ dqK
if(!fileSplitterFetch.bDownOver) @Reh?]# v
{ P^o"PKA
breakWhile = false; -v/?>
break; AmrJ_YP/t~
} |\{J`5gr
} {/,+_E/
if(breakWhile) \dQ2[Ek
break; [{Klv&>_/
b W`)CWd
`s|\"@2
//count++; _YD<Q@
//if(count>4) +eH=;8
// siteStop(); [jmAMF<F
} +L<w."WG
>u%[J!Y;;
eN7yjd'Y6
System.err.println("文件下载结束！"); C$EFh4
} QjT#GvHY
catch(Exception e){e.printStackTrace ();} 8?]%Qi
} =-#iXP@
_s=Pk[e
hPX2 Bp
//获得文件长度 ))we\I__8
public long getFileSize() `04Y ;@w
{ $4fjSSB~
int nFileLength = -1; //@sktHsw(
try{ A`mf 8'nTG
URL url = new URL(siteInfoBean.getSSiteURL()); L2Qp6A6S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Phjf$\pt
httpConnection.setRequestProperty("User-Agent","NetFox"); [eTck73
kdZ-<O7@
>goAf`sqo
int responseCode=httpConnection.getResponseCode(); V0wC@?
if(responseCode>=400) qoyGs}/I8
{ g^|_X1{
processErrorCode(responseCode); O,z%7><
return -2; //-2 represent access is error 1tK6lrhj
} =V4_DJ(&
vzT6G/
'@1Qx~*]e
String sHeader; 9/^Bj
q'U-{~q%
'e8d["N
for(int i=1;;i++) @a{v>)
{ E].a|4sh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); IcNIuv
//Utility.log(in.readLine()); ,J4a~fPf
sHeader=httpConnection.getHeaderFieldKey(i); -a#AE|`
if(sHeader!=null) 7dL=E"WL
{ ~(L<uFU V
if(sHeader.equals("Content-Length")) Fb`7aFIf
{ :/?R9JVI
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {/Q?
break; Y$DgL h
} *1 eTf
} zz''FmedF
else -V)5Tr=
break; EEnTq
} (]# JpQ
} s(DaPhL6Qm
catch(IOException e){e.printStackTrace ();} _J$p<
catch(Exception e){e.printStackTrace ();} mZ.6Njb
2QQYXJ^
fCo2".Tk
Utility.log(nFileLength); XVK[p=cIL
T;vPR,]rz
QSQ\@h;E
return nFileLength; JT+lWhy
} $1`t+0^k
,)\5O0 D6
`oI/;&
//保存下载信息（文件指针位置） ~+NFWNgN
private void write_nPos() X2mm'JDwK
{ h4xf%vA(;
try{ %EhU!K#[
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^bgm0,M
output.writeInt(nStartPos.length); iPi'5g(a
for(int i=0;i<nStartPos.length;i++) "r(pK@h
{ DT~y^h
// output.writeLong(nPos); pHbguoH,
output.writeLong(fileSplitterFetch.nStartPos); t~=@r9`S
output.writeLong(fileSplitterFetch.nEndPos); p[+me o
} LFry?HO,D
output.close(); Rhxm)5+
} At_Y$N:
catch(IOException e){e.printStackTrace ();} a5g{.:NfO
catch(Exception e){e.printStackTrace ();} RwLdV+2\R`
} ^oZs&+z
,lGwW8$R
?;kc%Rz
//读取保存的下载信息（文件指针位置） %>}7$Y%
private void read_nPos() Z["nY&.sI
{ >]N0w
try{ i!-sbwd7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {xx;zjt%}}
int nCount = input.readInt(); LfSUY
nStartPos = new long[nCount]; KQI} 5
nEndPos = new long[nCount]; PL2Q!i`[o
for(int i=0;i<nStartPos.length;i++) OX`GN#yl
{ FbT&w4Um=
nStartPos = input.readLong(); ].+G-<.:
nEndPos = input.readLong(); F nRxc
} 5nw9zW :'
input.close(); [ESQD5&
} o sH,(\4_
catch(IOException e){e.printStackTrace ();} @ dU3d\!}
catch(Exception e){e.printStackTrace ();} 4'e8VI0
} ue2nfp
u,k8i:JY
m!>'}z
private void processErrorCode(int nErrorCode) bWzc=03
{ yxq!.72
System.err.println("Error Code : " + nErrorCode); X-^Oz@.>
} 8o!^ZOmU<
y#W8] <dS"
5rSth.&
//停止文件下载 aWK7 -n
public void siteStop() 2xxwQwg8
{ \O4=mJ
bStop = true; n;Wf|>
for(int i=0;i<nStartPos.length;i++) {oC69n:
fileSplitterFetch.splitterStop(); DcM+K@1E4^
`SbX`a0p2
aQuy*\$$
} zL{@LHP
} g5'bUYsa
//负责部分文件的抓取 yc}t(*A5
**FileSplitterFetch.java AR2+W^aM3
*/ cLF>Jvs*J
package NetFox; :Fk&2WsW:
U}h |Zk
yUlQPrNX
import java.io.*; t`D@bzLC%
import java.net.*; f}uCiV!?v
"qp_*Y
tHo/uW_~I
public class FileSplitterFetch extends Thread { (G;*B<|A
R-|]GqS}L
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String sURL; //File URL )y Y;%
long nStartPos; //File Snippet Start Position bhT]zsBK
long nEndPos; //File Snippet End Position 2UJ0%k
int nThreadID; //Thread's ID {u][q &n
boolean bDownOver = false; //Downing is over id9T[^h
boolean bStop = false; //Stop identical +u.L6GcB
FileAccessI fileAccessI = null; //File Access interface f%l#g]]
? +!?$h
T}On:*&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tq93 2M4
{ M_uij$1-
this.sURL = sURL; #&gy@!a~
this.nStartPos = nStart; c9k,Dc
this.nEndPos = nEnd; B75SLK:h=
nThreadID = id; >,1LBM|0u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y5pNKL
} {1ceF
(]dZ+"O{
<H#K`|Ag
public void run() j3F=P
{ *mtv[
while(nStartPos < nEndPos && !bStop) r4zS,J;,
{ zK;t041e
351'l7F\
?Fw/c0
try{ }_TdXY #w\
URL url = new URL(sURL); 8h2?Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [b'fz
httpConnection.setRequestProperty("User-Agent","NetFox"); KfS^sT
String sProperty = "bytes="+nStartPos+"-"; } 4^UVdz
httpConnection.setRequestProperty("RANGE",sProperty); >{8H==P
Utility.log(sProperty); Grv|Wuli
wkw/AZ{27
Wn5]2D\vkT
InputStream input = httpConnection.getInputStream(); 0^^i=iE-u
//logResponseHead(httpConnection); ('oUcDOFTS
JASn\z
C I0^eaFs
byte[] b = new byte[1024]; Czn7,KE8X
int nRead; 4v$AM8/o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4[wP$
{ :r=_\?
nStartPos += fileAccessI.write(b,0,nRead); Pl>t\`1:|A
//if(nThreadID == 1) BO|Jrr>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =)LpMTz
} a#=-Aj-
=7>~u
QJ?!_2Ax
Utility.log("Thread " + nThreadID + " is over!"); st>t~a|T
bDownOver = true; tp&iOP6O
//nPos = fileAccessI.write (b,0,nRead); 4dAhJjhgD
} J>Ha$1}u/
catch(Exception e){e.printStackTrace ();} f|)t[,c
} rG6/h'!|
} 03T.Owd
FW,D\51pTP
Y@eUvz
//打印回应的头信息 L&%iY7sC`
public void logResponseHead(HttpURLConnection con) HVpaVM
{ 6h%(0=^
for(int i=1;;i++) 95/C4q
{ Yn/-m Z
String header=con.getHeaderFieldKey(i); 1F/&Y}X
if(header!=null) CXA8V"@&b/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hpu(MX\
Utility.log(header+" : "+con.getHeaderField(header)); c#Bde-dh
else m`cG&Ar5
break; !T)>q%@ai
} 3[4]G@
} P8f-&(
Pe.D[]S
We2=|AB
public void splitterStop() ZWH`s
{ |)?T([
bStop = true; U$}]zaB
} w.\:I[
th{h)( +H
G 2##M8:U0
} ;d4_l:9p
&[uGfm+@
CDhk!O..
/* h?sh#j6
**FileAccess.java c-F&4V
*//文件访问(定位，写) >8so'7(
package NetFox; YuZnuI@m9
import java.io.*; )C[8#Q-:
]Az >W*Y
-|5&3HVz
public class FileAccessI implements Serializable{ ' BpRiN
ge|}'QKow
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4kiu*T
RandomAccessFile oSavedFile; eJ'ojc3
long nPos; jiat5
d {4br
tx.sUu6
public FileAccessI() throws IOException apXq$wWq{D
{ 'Tn$lh
this("",0); ]So%/rOvX
} N*#SY$!y
G(>a LF
6*E7}
public FileAccessI(String sName,long nPos) throws IOException eM}Xn^}
{ _F9 c.BH
oSavedFile = new RandomAccessFile(sName,"rw"); ;%}
this.nPos = nPos; J{Jxb1:c
oSavedFile.seek(nPos); q!n|Ju<
} 4{V=X3,x
<Ip}uy[Y
O;~1M3Ii
public synchronized int write(byte[] b,int nStart,int nLen) W$W7U|Z9y+
{ tF4"28"h
int n = -1; z|Xl%8
try{ N.]8qzW
oSavedFile.write(b,nStart,nLen); =B\?(
n = nLen; hn-S$3')`
} ;rX4${h
catch(IOException e) <}evOw2
{ /T?['#:r-)
e.printStackTrace (); hikun2
} ji "*=i
2&M 8Wb#
PQ j_j#0
return n; 2neiUNT
} xGqZ8v`v
Lt)t}0
vCJjZ%eO%D
} :mij%nQ>$
BkcOsJIz
nxG vh4'i8
/* jGt[[s
**SiteInfoBean.java _$\T;m>'A
*/ Ky+TgR
package NetFox; D_@^XS
b|EZ;,i
)vw3Y88
public class SiteInfoBean { ~o+u:]
j=7]"%
;fuy}q8@7
private String sSiteURL; //Site's URL hod|o1C&
private String sFilePath; //Saved File's Path #8'%CUF*<8
private String sFileName; //Saved File's Name OHB!ec6W
private int nSplitter; //Count of Splited Downloading File oD.f/hi0|
Fw|5A"9'a'
iS"rMgq
public SiteInfoBean() x`$4
{//nSplitter的缺省值为5 [p(Y|~
//default value of nSplitter is 5 :)+cI?\#
this("","","",5); Tsa&R:SE
} 9s}--_k?F2
h5~tsd}OU
-" DI,o
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |XQ!xFB
{ '1d-N[
sSiteURL= sURL; P/27+5(|
sFilePath = sPath; !=a8^CV
sFileName = sName; 9%4rO\q
this.nSplitter = nSpiltter; e|`&K"fnq
Lm8cY
)ZT&V I
} _:{XL c
N-suBRnW
q*2ljcb55
public String getSSiteURL() il*bsnwpZv
{ )J0'We
return sSiteURL; sx6` g;
} ='~C$%
P",53R+"
2lQ'rnqS)
public void setSSiteURL(String value) rK];2[U
{ u+hzCCwtR
sSiteURL = value; T\OLysc
} z*:^*,
%hY+%^k.
}lhJt|qc
public String getSFilePath() /q8n_NR
{ BH=vI<D
return sFilePath; eI- ~ +.
} $L?stgU
&DgIykqN
Y1+f(Q
public void setSFilePath(String value) WO]dWO6Mm
{ m~#O ~)
sFilePath = value; zp d4uto5
} x}-rAr
gCd9"n-e
zc(-dMlK
public String getSFileName() t0/fF'GZD
{ sURHj&:t|
return sFileName; TzVNZDQ`Jl
} Z[|(}9v?~
!IP[C?(nB
k)'c$
public void setSFileName(String value) 0LxA+
{ ;gf^;%FK
sFileName = value; w+PbT6;
} 1'M<{h<sP
}nuhLt1
\07 s'W U
public int getNSplitter() 8eL[,uw
{ V"gnG](2l
return nSplitter; &AC-?R|Dp
} %T!UEl`v
jh9^5"vQ
"{|9Yis=
public void setNSplitter(int nCount) r%F{1.
{ FD[*mCGZ
nSplitter = nCount; )'92{-A0
} pkhZW8O
} 4u A;--j
g {wDI7"<q
]x! vPIyq
/* 5WY..60K,
**Utility.java A\gj\&B0"
*/ T5o9pmD
package NetFox; R|`}z"4C
#}l}1^$
#BF(#1:
public class Utility { gZ:)l@ Wu
.BuY[,I+
WC0@g5;1[
public Utility() LKtr>u
{ pz~AsF
)N<>L/R
8&B{bS
} sJ25<2/
9w(QM-u
//线程睡眠 Rax}r
public static void sleep(int nSecond) ewD61Y8-
{ "C%;9_ig$
try{ o^2.&e+dQ
Thread.sleep(nSecond); n~k;9`
} (yn!~El3
catch(Exception e) L3'o2@$
{ 5YJLR;
e.printStackTrace (); 5Tkh6s
} =]E;wWC
} j?#S M!f
e$fxC-sZ
//日志 c(i-~_
public static void log(String sMsg) s9zdg"c'
{ 0O|T\E8e
System.err.println(sMsg); e%o6s+"
} >DpnIWn
-(@dMY
"EDn;l-Q
public static void log(int sMsg) p~En~?<
{ 3T%WfS+
System.err.println(sMsg); 8}nA8J
} }r9f}yX9Q
} 3;@t{rIin
_z#zF[%
;VNwx(1l`
/* W_ngB[
**TestMethod.java ^;!A`t
*/ +3!um
package NetFox; `dx+Qp
JO1KkIV
/m(vIl
public class TestMethod { U_y)p Cd
:;#Kg_bz
\&n]W\
public TestMethod() KzG8K 6wZ
{ ///xx/weblogic60b2_win.exe 8!'#B^
try{ ;a*i*{\Rm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T1LtO O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @I_A\ U{
SiteFileFetch fileFetch = new SiteFileFetch(bean); J#!:Z8b
fileFetch.start(); eOE7A'X
} P BpjE}[Q
catch(Exception e){e.printStackTrace ();} ?x%HQ2`
1.]#FJe
R4%!W~K
} &1{RuV&t
4hr;k0sD
#swzZyM$
public static void main(String[] args) 3#j%F
{ W -8<sv$b
new TestMethod(); n'U*8ID
} "9>~O`l,
} IF(W[J
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