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)); w[G-=>;
} ZT,auSX
for(int i=0;i<nEndPos.length-1;i++) PAVlZ}kj
{ Upm#:i|"
nEndPos = nStartPos[i+1]; "g(q)u >
} $lJ!f
nEndPos[nEndPos.length-1] = nFileLength; */vid(P77
} |@?='E?h
} kpk ^Uw%f
FE#|5;q.
ONc#d'-L
//启动子线程 8zwH^q[`r
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; f,BJb+0
for(int i=0;i<nStartPos.length;i++) ]HRHF'4
{ DvA#zX[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m5hu;>gt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), EAF\7J*
nStartPos,nEndPos,i); z,VXH ?.Zo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 77 ?TRC
fileSplitterFetch.start(); sr~VvciIy
} `2xt%kC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C3 m_sv#e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Gr3 q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !=+;9Ry$z
nEndPos = " + nFileLength); Q0xQxz
// fileSplitterFetch[nPos.length-1].start(); Z(J 1A x
w}29#F\]R
48!F!v,j)x
//等待子线程结束 ]!@!qp@
//int count = 0; J.0&gP V
//是否结束while循环 TJ,?C$3
boolean breakWhile = false; F[fs^Q6S$
Kke _?/fT
U/7jK40
while(!bStop) uR!'v
{ }E)t,T>
write_nPos(); s2nZW pIy
Utility.sleep(500); eE{ 2{C
breakWhile = true; Y2+YmP*z`
va.Ve# N
)P.,h&h/
for(int i=0;i<nStartPos.length;i++) [c99m:*+
{ sr:hRQ27
if(!fileSplitterFetch.bDownOver) rj<-sfs
{ >waA\C}
breakWhile = false; _G)x\K]N
break; -1R7 8(1
} 2%]#rZ
} `Cu9y+t
if(breakWhile) t4-0mNBZt$
break; fY|vq amA;
~\c j
pFwe&_u]
//count++; pf3-
//if(count>4) ww\2
// siteStop(); c>C!vAg
} O@rZ^Aa
vLCm,Bb2L
dBW4%Zh
System.err.println("文件下载结束！"); 4_4|2L3
} G2J4N2hu
catch(Exception e){e.printStackTrace ();} FWS!b!#,N
} BkDq9>
CTc#*LJx>j
t1aKq)?
//获得文件长度 ay=f1<a
public long getFileSize() #;'*W$Wk2
{ ck8Qs08
int nFileLength = -1; TG.\C8;vFh
try{ qmnW
URL url = new URL(siteInfoBean.getSSiteURL()); ,w_C~XN$t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g;y*F;0@
httpConnection.setRequestProperty("User-Agent","NetFox"); 5WtI.7r
&hzr(v~;
1w>G8
int responseCode=httpConnection.getResponseCode(); o6r ^
if(responseCode>=400) jgw+c3^R_
{ k6_OP]
processErrorCode(responseCode); ITjg]taD
return -2; //-2 represent access is error "%=K_WJ?
} a#3,qp!
p vu% p8
1qwJPM
String sHeader; yIS&ZtBA
ab<7jfFIa
77G4E ,]
for(int i=1;;i++) ~@iYP/=/Q
{ 1,6Y)_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?/KkN3Y_j[
//Utility.log(in.readLine()); H"|oI|~
sHeader=httpConnection.getHeaderFieldKey(i); ;{g>Z|
if(sHeader!=null) rrZ'Dz
{ v<?k$ e5
if(sHeader.equals("Content-Length")) PO=A^b
{ 8noo^QO
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xllmF)]*Y
break; 7L!q{%}
} )/t=g
} &F +hh{
else RD*.n1N1
break; %#7^b=;=
} HOVzpj
} 0&2&F=fOa<
catch(IOException e){e.printStackTrace ();} $H7T|`WI.,
catch(Exception e){e.printStackTrace ();} a3BlydSlf
SvD:UG
)"^ )Nk
Utility.log(nFileLength); Y-*]6:{E
*&W1|Qkg_
BctU`.
return nFileLength; zMAlZ[DN
} |JCn=v@
U6_GEBz~y
kn6X I*
//保存下载信息（文件指针位置） <t. w(?
private void write_nPos() RSf*[2
{ l' a<k"
try{ n UD;y}}n
output = new DataOutputStream(new FileOutputStream(tmpFile)); x^6sjfAW
output.writeInt(nStartPos.length); 0'^zIL#.
for(int i=0;i<nStartPos.length;i++) [moz{Y
{ K#'{Ko
// output.writeLong(nPos); 8'Bik
output.writeLong(fileSplitterFetch.nStartPos); 1V2"sE
output.writeLong(fileSplitterFetch.nEndPos); :8Jn?E (36
} >*[Bq;
output.close(); 0D48L5kH#'
} 4[m4u6z=
catch(IOException e){e.printStackTrace ();} %!Ak]|[7
catch(Exception e){e.printStackTrace ();} P 4jg]g
} uVV;"LVK~
]_P!+5]<
8w4cqr4m
//读取保存的下载信息（文件指针位置） WiclG8l
private void read_nPos() 8{J{)gF
{ G+f@m,
try{ _#6ekl|%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y,C3E>}Dq
int nCount = input.readInt(); s4Z5t$0|
nStartPos = new long[nCount]; -<WQ>mrB&
nEndPos = new long[nCount]; %wS5m#n
for(int i=0;i<nStartPos.length;i++) [|\BuUT'
{ \^rAH@
nStartPos = input.readLong(); <YBA 7i
nEndPos = input.readLong(); *ZA.O
} bcZ s+FOPd
input.close(); 0=Z_5.T>
} D<*#. >
catch(IOException e){e.printStackTrace ();} 66l$}+|Zzc
catch(Exception e){e.printStackTrace ();} B*j AD2
} 2x&mJ}o#k
QBfsdu<@^
'Ijjk`d&c
private void processErrorCode(int nErrorCode) (E(kw="
{ Z'L}x6
System.err.println("Error Code : " + nErrorCode); ~T<o?98
} y%x2
^3 '7
F;^GhiQVS
//停止文件下载 $^4URH
public void siteStop() 5//.q;z
{ SB'$?Kh
bStop = true; }J&[Uc
for(int i=0;i<nStartPos.length;i++) :TzHI
fileSplitterFetch.splitterStop(); d*xKq"+ &E
6P KH%
4RV5:&ALLS
} U[UjL)U
} !mLYW
//负责部分文件的抓取 5>'1[e45
**FileSplitterFetch.java I`e|[k2
*/ J 4EG
package NetFox; 3<nd;@:-
%}asw/WiUa
{qHf%y&[
import java.io.*; U`fxe`nVa
import java.net.*; ]Kb3'je
XVKR}I
2nGQD{
public class FileSplitterFetch extends Thread { > %U
n/fMq,<8
1]uHaI(
String sURL; //File URL _n;V iQMu
long nStartPos; //File Snippet Start Position *?Sp9PixP
long nEndPos; //File Snippet End Position jI(}CT`g
int nThreadID; //Thread's ID EJrn4QOs
boolean bDownOver = false; //Downing is over JtrLTo
boolean bStop = false; //Stop identical ,U#$Qb 12
FileAccessI fileAccessI = null; //File Access interface T>ds<MaLP
>1=sw qa
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j7|r^
{ ;nbUbRb
this.sURL = sURL; OJL?[<I
this.nStartPos = nStart; Dog Tj
this.nEndPos = nEnd; tNI~<#+lg
nThreadID = id; p Rn vd|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pZ,P_?
} *hp3w
W:^\Oe5&a
PKhH0O\_U
public void run() jz_\B(m9%
{ mG!Rh
while(nStartPos < nEndPos && !bStop) $DOBC@xxzT
{ [C]u!\(IF
=*aun&
H"H&uA9"
try{ 6jiz$x
URL url = new URL(sURL); pbe" w=<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'W/E*O6BY
httpConnection.setRequestProperty("User-Agent","NetFox"); h<50jnH!
String sProperty = "bytes="+nStartPos+"-"; A7!=`yA$
httpConnection.setRequestProperty("RANGE",sProperty); W`KRaL0^
Utility.log(sProperty); j`Xe0U<
R&BbXSIDX
5__8+R
InputStream input = httpConnection.getInputStream(); 0?]*-wvp
//logResponseHead(httpConnection); 7ZbnG@s7
8lo /BGxS>
{BBL`tg60
byte[] b = new byte[1024]; Azun"F_f
int nRead; [WDtr8L
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) AKVll
{ gu[3L
nStartPos += fileAccessI.write(b,0,nRead); 0i2ZgOJ
//if(nThreadID == 1) DbdxHuKa>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cCd2f>EHw
} );*A$C9RA
E}aTH
:bxq%D%|o
Utility.log("Thread " + nThreadID + " is over!"); LY%`O#i.
bDownOver = true; Cebl"3Q
//nPos = fileAccessI.write (b,0,nRead); G!J{$0.
} x;,H>!r"i
catch(Exception e){e.printStackTrace ();} ]urrAIK
} ^d!(8vh
} *7'}"@@
`k}
iol.RszlZ|
//打印回应的头信息 cNzn2-qv
public void logResponseHead(HttpURLConnection con) }5Yd:%u5
{ v*+.;60_
for(int i=1;;i++) 'OKDB7Ni
{ 5gV%jQgkC
String header=con.getHeaderFieldKey(i); beyC't
if(header!=null) Farcd!}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /`YHPeXu
Utility.log(header+" : "+con.getHeaderField(header)); #\kYGr-G)
else %Y"@VcN
break; tl|Qw";I
} Zk*/~f|\
} Cf'O*RFD
8-Ik .,}
je6H}eWTC6
public void splitterStop() vDgf}
{ :^+ aJ]
bStop = true; K8{Ub
} tkBp?Wl
0p\cDrB?
^Jb=&u$
} zK`z*\
\K+LKa)
}v[*V
/* z\Vu`Yz
**FileAccess.java ^zPa^lo-
*//文件访问(定位，写) ;Ub;AqY
package NetFox; u%FG% j?C
import java.io.*; &h.E B
^NB@wuf7
w,(e,8#:
public class FileAccessI implements Serializable{ )K2,h5zU
F0O"rN{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2)DrZI
RandomAccessFile oSavedFile; q| p6UL9
long nPos; {FO>^~>l
6$TE-l
d(RSn|[0
public FileAccessI() throws IOException u|l]8T9L
{ kYwk'\s
this("",0); !ydJ{\;
} l$$N~FN
}~Z1C0t
PaPQ|Pwz
public FileAccessI(String sName,long nPos) throws IOException ]+O];*T
{ e;:~@cB,c
oSavedFile = new RandomAccessFile(sName,"rw"); ", b}-B
this.nPos = nPos; &K@2kq,
oSavedFile.seek(nPos); DN)Ehd.
} SV;S`\i
LJK<Xen
ngM>Tzirt
public synchronized int write(byte[] b,int nStart,int nLen) W)I)QinOH
{ x/Pi#Xm
int n = -1; v=15pW
try{ nlaJ
oSavedFile.write(b,nStart,nLen); E5.3wOE
n = nLen; LyM"
} 2fp\s5%J}
catch(IOException e) WyH2` xxX
{ $Yh7N5XH,
e.printStackTrace (); FCv3ZF?K
} sr!m
*6%!i7kr
f6x}M9xS%
return n; {7!WtH;-
} 1A;>@4iC0
E"7 iU
5tMp@$F\{[
} vy?Zz<c;
6;g_}Zx
zj.;O#hW
/* >]?!c5=
**SiteInfoBean.java c`w YQUg(
*/ 8KKI.i8`
package NetFox; F+r3~T%
zCxr]md
8 ;oU{
public class SiteInfoBean { AL%H$I
&UtsI@Mu
B>, O@og
private String sSiteURL; //Site's URL yD|He*$S
private String sFilePath; //Saved File's Path 2Uf]qQ1
private String sFileName; //Saved File's Name W$=MuF7R
private int nSplitter; //Count of Splited Downloading File C<Q;3w`#1j
Tl9KL%9
_MfXN$I?}
public SiteInfoBean() g+Z~"O]$M
{//nSplitter的缺省值为5 &Pu}"M$[MH
//default value of nSplitter is 5 _]W {)=ap
this("","","",5); Ar4@7
} Z)B5g>
-}nTwx:|5u
1DPgiIG~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $y~!ePKh
{ i,jPULzyjk
sSiteURL= sURL; B\BxF6 y
sFilePath = sPath; kWs"v6B
sFileName = sName; ;2X/)sxWz
this.nSplitter = nSpiltter; h^#K4/
5(kRFb'31F
wmh[yYWc
} :|i jCg+
umV5Y`
/ 0Z_$Q&e
public String getSSiteURL() bM`7>3 d7E
{ |,k,X}gP
return sSiteURL; ?0HPd5=<v
} 0KknsP7
sr(f9Vl
0^htwec!
public void setSSiteURL(String value) /(-X[[V
{ qI,4uGg
sSiteURL = value; |ho|Kl `=
} Ba-Ftkb
ts rcX
C]{:>= K
public String getSFilePath() r9@4-U7v&
{ xB=~3
return sFilePath; ~$7fU
} ^3*k6h[(
:n36}VG|
Z3Le?cMt^
public void setSFilePath(String value) _B4H"2}[Y
{ {VOLUC o 4
sFilePath = value; gGl}~
} Zr`pOUk!4
8jyg1NN D
r|[uR$|Y
public String getSFileName() (xnXM}M&2Y
{ e-vwve
return sFileName; 4?GW]'d
} W|S{v7[l
Cf#[E~24
M7rVH\:[-
public void setSFileName(String value) Ic_>[E?k
{ (h;4irfX
sFileName = value; >gNVL (
} `4V_I%lJ&
$ K>.|\
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public int getNSplitter() %j4
{ &HdzbKO=
return nSplitter; Qp9)Rc5
} G-?y;V 1
E;7vGGf]
]mEY/)~7
public void setNSplitter(int nCount) t)Q6A@$:
{ Ra%" +=
nSplitter = nCount; l*;Isz:
} V@6,\1#`|
} :sD/IM",},
8.9TWsZ
A1`y_ Aj
/* =<nx[J
**Utility.java 7VWq8FH`
*/ A|!u`^p
package NetFox; |> mx*G
WVPnyVDc
biZwxP3
public class Utility { uh`W} n
cfn\De%.
rv/O^aL`Y
public Utility() 8 /3`rEW
{ 58FjzW
~s_n\r&23
@"[xX}xK;
} P{qi>FJqe
4RgEN!d?H
//线程睡眠 L~nVoKY*V
public static void sleep(int nSecond) %W!C
{ &m@~R|
try{ r=8(n<;Co
Thread.sleep(nSecond); V[&4Km9C
} t#pF.!9=
catch(Exception e) x[]}Jf{t
{ (+Ia:D
e.printStackTrace (); D@5Ud)_
} Er; @nOyD
} h*J=F0KM
hdZ{8 rP
//日志 SM3Q29XIw
public static void log(String sMsg) {<f_,Nlc
{ S%ULGX:@ga
System.err.println(sMsg); ESdjDg$[u
} :{za[,
N5$IVz}
.qBL.b_`
public static void log(int sMsg) qcYF&
{ y%* hHnGd
System.err.println(sMsg); YKF5|;}
} yQ5F'.m9e
} `Mj>t(
Y](kMNUSg
B J,U,!
/* di^E8egR$
**TestMethod.java j. 1@{H
*/ ` drds
package NetFox; p$r=jF&
~";GH20
m0XdIC]s
public class TestMethod { cuenDw=eC
k+8K[?K-
^HpUbZpat)
public TestMethod() xO2e>[W
{ ///xx/weblogic60b2_win.exe :by EXe;3
try{ ySyA!Z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gmG M[c\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =pQ'wx|>|
SiteFileFetch fileFetch = new SiteFileFetch(bean); Uy8r !9O
fileFetch.start(); {FV_APL9_
} ZH]n&%@j
catch(Exception e){e.printStackTrace ();} S.,om;`
^Fmp"[q
yk1.fxik'
} AcF6p)@_
P+tnXT>nE
zoFCHsr
public static void main(String[] args) ZaxBr
{ E+>$@STv#
new TestMethod(); |3tq.JU
} UPs7{We W
} eBw6k09C+
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