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)); sb Wn1 T U
} 9`P<|(
for(int i=0;i<nEndPos.length-1;i++) G%{J.J41F
{ |,*N>e
nEndPos = nStartPos[i+1]; :+%"kgJNL
} 4K_rL{s0U
nEndPos[nEndPos.length-1] = nFileLength; 'Vwsbm tY
} Zj@k3y
} Arg604V3
d"K~+<V}
Zd~'%(q
//启动子线程 .+|HJ(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /5qeNjI+2
for(int i=0;i<nStartPos.length;i++) !~+"TI}_%w
{ 'R&Y pR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WmO.&zp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )-D{]>8
nStartPos,nEndPos,i); C`s
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !c}?u_Z/
fileSplitterFetch.start(); .<0|V
} [{]/9E/&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5K_KZL-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); N/wUP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C|#GODA
nEndPos = " + nFileLength); 42*y27Dtm
// fileSplitterFetch[nPos.length-1].start(); :ud<"I]:
0(!j]w"r3
K`7(*!HEb
//等待子线程结束 4+rr3 $AY
//int count = 0; bXVH7Fy
//是否结束while循环 /.54r/FN')
boolean breakWhile = false; ZY_aE
F E`4%X
vL>cYbJ<
while(!bStop) _[D6WY+
{ *C/bf)w
write_nPos(); ,t"?~Hl".
Utility.sleep(500); =<,>dBs}\
breakWhile = true; yQAW\0`
Y nD_:ZK
:c4iXK0_^?
for(int i=0;i<nStartPos.length;i++) %N jRD|
{ (OA-Mgyc
if(!fileSplitterFetch.bDownOver) ]>j>bHG
{ OVwcjhQ
breakWhile = false; /y8=r"'G
break; #~3$4j2U(y
} iME)Jl&
} !V<c:6"
if(breakWhile) vJybhdvP
break; #%Z 0!
3X&'hz@
O!uZykdX4!
//count++; K fM6(f:
//if(count>4) <+7]EwVcn^
// siteStop(); Ue:LKK1Gsr
} vBFMne1h
y {&"g
M)m(
System.err.println("文件下载结束！"); vy:-a G
} GSHJ?}U,
catch(Exception e){e.printStackTrace ();} %pikt7,Z~
} (8JL/S;Z$
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7D5[ L
//获得文件长度 ;kW+
public long getFileSize() F0.Rv):
{ WruSL|4iH
int nFileLength = -1; sBN"eHg
try{ QcW6o,
URL url = new URL(siteInfoBean.getSSiteURL()); , %8keGhl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kGz0`8URu
httpConnection.setRequestProperty("User-Agent","NetFox"); Ox| ?
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}u3Q*oAGl
int responseCode=httpConnection.getResponseCode(); ; 9n}P@
if(responseCode>=400) P\jnht
{ _*K=Z,a;\
processErrorCode(responseCode); fT]hpoJl
return -2; //-2 represent access is error Ch] `@(l
} ,.<[iHC}9
B=?m_4\$m
=nVEdRU
String sHeader; N7Kg52|
hSl6X3W
O V"5:){
for(int i=1;;i++) `;`fA|F^
{ VVd9VGvh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [6ycs[{!
//Utility.log(in.readLine()); 4Nb&(p
sHeader=httpConnection.getHeaderFieldKey(i); ''Pu
if(sHeader!=null) U4$}8~o4
{ Jw+k=>
if(sHeader.equals("Content-Length")) tv]^k]n{rf
{ Quq X4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i%FpPni
break; =pT}]
} `@_jDo
} %qycxEVP
else 0uZL*4A+C
break; 8I>'xf
} ??]b,f4CNa
} %%-?~rjI
catch(IOException e){e.printStackTrace ();} qsA`\%]H
catch(Exception e){e.printStackTrace ();} u5'jIqlU
@K=:f
8|cQW-L
Utility.log(nFileLength); q PveG1+25
Qhc>,v)
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return nFileLength; OMY^'g%w
} De<kkR{4
d`w3I`P1
'K!u}py
//保存下载信息（文件指针位置） gN/kNck
private void write_nPos() IYG,nt!
{ S5+W<Qs
try{ fb=[gK#*,
output = new DataOutputStream(new FileOutputStream(tmpFile)); ku3(cb!2
output.writeInt(nStartPos.length); -:V0pb
for(int i=0;i<nStartPos.length;i++) hifC.guK
{ E"'4=_
// output.writeLong(nPos); (r9W[
output.writeLong(fileSplitterFetch.nStartPos); }J^+66{
output.writeLong(fileSplitterFetch.nEndPos); ZRy'lW
} >)j`Q1Qc\
output.close(); rOo|.4w
} nb30<h
catch(IOException e){e.printStackTrace ();} 0en Bq>vr
catch(Exception e){e.printStackTrace ();} _xmS$z)TO
} i-YSt5iq
{<P{uH\l
b(HbwOt~3
//读取保存的下载信息（文件指针位置） K ; eR)
private void read_nPos() Z,"f2UJ
{ "9v4'"
try{ ]aZ3_<b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %wQE lkB
int nCount = input.readInt(); qS!U1R?s
nStartPos = new long[nCount]; q; ?Kmk
nEndPos = new long[nCount]; />X"'G
for(int i=0;i<nStartPos.length;i++) SZVAf|]Yg
{ 7Eo;TNbb
nStartPos = input.readLong(); <*3#nA-O>i
nEndPos = input.readLong(); )JXlPU
} c}G\F$
input.close(); bH Nf>
} 5OM*NT t
catch(IOException e){e.printStackTrace ();} '89nyx&W
catch(Exception e){e.printStackTrace ();} .At^b4#(
} qa>H@`P
~(x"Y\PEu
EEp~\^-
private void processErrorCode(int nErrorCode) ra|Ku!
{ 3+WmM4|
System.err.println("Error Code : " + nErrorCode); dr gCr:Gf
} x:E:~h[.^
([ODmZHv
h|{DIG3
//停止文件下载 CeINODcT
public void siteStop() o:c:hSV
{ MC~<jJ,
bStop = true; O$(#gB'B
for(int i=0;i<nStartPos.length;i++) QB<~+dW
fileSplitterFetch.splitterStop(); M\D25=(
x>GxyVE
9YvK<i&I
} <i ";5+
} 7?p>v34A
//负责部分文件的抓取 Vv_lBYV
**FileSplitterFetch.java V$fn$=
*/ s?7"iE
package NetFox; }G ^nK m
*cy!PF&
1a tQ9
import java.io.*; Zq"
import java.net.*; &Vy.)0
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ZkqZO#nq C
public class FileSplitterFetch extends Thread { *[+{KJ
nU,~*Us
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String sURL; //File URL ?_j]w%Hz
long nStartPos; //File Snippet Start Position 1xDh[:6
long nEndPos; //File Snippet End Position q+U&lw|"w
int nThreadID; //Thread's ID !%(PN3*
boolean bDownOver = false; //Downing is over #:xv]qb`k
boolean bStop = false; //Stop identical sP@7%p>wt
FileAccessI fileAccessI = null; //File Access interface zI$'D|A
YZZog6%
/wPW2<|"X.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .OZ\s%h;
{ !7n`-#)
this.sURL = sURL; 6B!v;93U
this.nStartPos = nStart; &R,QJ4L
this.nEndPos = nEnd; 6$&%z Eh
nThreadID = id; -u^f;4|u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y-.aSc53
} XaH;
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public void run() xp F(de
{ v!j%<H`NI
while(nStartPos < nEndPos && !bStop) ?D+H2[n\a
{ _BI[F m
}=fls=c/0
u,JUMH]@
try{ 2. f8uq
URL url = new URL(sURL); W=I~GhM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Wrf+5 ;,,
httpConnection.setRequestProperty("User-Agent","NetFox"); 4l@aga
String sProperty = "bytes="+nStartPos+"-"; 'kHa_
httpConnection.setRequestProperty("RANGE",sProperty); Q#lFt,.y
Utility.log(sProperty); Huc|HL#C
Vx%!j&
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InputStream input = httpConnection.getInputStream(); q"u,r6ED
//logResponseHead(httpConnection); oC}2 Z{
L}VQc9"gc
^+O97<#6C
byte[] b = new byte[1024]; B=HEi\55K
int nRead; A2''v3-h8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 59H~qE1Md
{ ~_|CXPiQ8
nStartPos += fileAccessI.write(b,0,nRead); `k-|G2
//if(nThreadID == 1) a,eEP43dn
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h|.{dv
} !X\aZ{}Q
dZ x
->'xjD
Utility.log("Thread " + nThreadID + " is over!"); '[p0+5*x
bDownOver = true; U nS|""
//nPos = fileAccessI.write (b,0,nRead); +&[X7r<
} Z@i,9 a
catch(Exception e){e.printStackTrace ();} km29]V=}
} -/R?D1kOq
} "DSRyD0M
9P*p{O{_
1"No~/_
//打印回应的头信息 LJOJ2x
public void logResponseHead(HttpURLConnection con) VgO.in^q
{ #]J"j]L
for(int i=1;;i++) f@ .s(i=z
{ =D Tbz3<
String header=con.getHeaderFieldKey(i); q>m[vvt"
if(header!=null) gT2k}5d}p
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 22Oe~W;
Utility.log(header+" : "+con.getHeaderField(header)); >NZJ-:t
else il7gk<
break; {-51rAyi
} $AHdjQ[;6-
} }CvhLjo
cHon' tS
6|Xm8,]yRw
public void splitterStop() }'4aW_ta
{ ;FnS=Z
bStop = true; OE2r2ad
} pE6r7
@;Xa&*
GriFb]ml"
} %JuT'7VB
W];l[D<S*
ivvm.7{
/* lL*"N|Y
**FileAccess.java v\R-G
*//文件访问(定位，写) f`-UC_(;
package NetFox; MS& 'Nj
import java.io.*; Asli<L(?`
9:7&`JlC#
ddEV@2F
public class FileAccessI implements Serializable{ G"U^]$(+K
W_[ tdqey
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U,V+qnS
RandomAccessFile oSavedFile; *rmM2{6
long nPos; l8+;)2p!
ft?c&h;At
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public FileAccessI() throws IOException R T/)<RT9
{ ]%+T+zg(Y
this("",0); 3ZhuC".c
} I~ e,']
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|9]_<X[ic
public FileAccessI(String sName,long nPos) throws IOException 9lB$i2G>Zw
{ ;]_h")4"c
oSavedFile = new RandomAccessFile(sName,"rw"); g1&q6wCg|
this.nPos = nPos; > mEB,
oSavedFile.seek(nPos); vvF]g.,
} 0?=a$0_C
U<wM#l P|Z
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public synchronized int write(byte[] b,int nStart,int nLen) &e99P{\D
{ u6iX&%e
int n = -1; )pG*_q
try{ 98lz2d/Fcq
oSavedFile.write(b,nStart,nLen); j>Cp4
n = nLen; ,=dc-%J
} g])iU9)8
catch(IOException e) ,OBJ>_5
{ .DHQJ|J-1
e.printStackTrace (); mJ+mTA5bW
} =}2k+v-B
unt{RVR%
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return n; ;-8]
} $tDM U3,W
R,m|+[sl
]p8<Vluv
} 41I2t(H @z
$8>II0C.
t"X^|!hKIF
/* [!U! Z'i
**SiteInfoBean.java N_?15R7h
*/ ?fQ8Ff
package NetFox; ~r&+18Z;
+Os9}uKf
t<MO~_`!
public class SiteInfoBean { !H~PF*,hY
oq2-)F2/
O8/r-?4.
private String sSiteURL; //Site's URL ]4]AcJj
private String sFilePath; //Saved File's Path EC7)M}H
private String sFileName; //Saved File's Name n,`j~.l-=>
private int nSplitter; //Count of Splited Downloading File NV`=T?1[5
g:Ry.=F7W
9}'92
public SiteInfoBean() 8@7leAq!
{//nSplitter的缺省值为5 Pp`[E/ qj4
//default value of nSplitter is 5 *&~ '
this("","","",5); =" pNE#
} WMnxN34
X-`PF
_Q7]Dw/w\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nf,Ez
{ ;Hn>Ew
sSiteURL= sURL; Ys8D|HIk
sFilePath = sPath; ;:'ABfs
sFileName = sName; j9&x#U
this.nSplitter = nSpiltter; na_Wp^;
t""d^a#Dp
yQ| V7G
} (1)b> 6
lF~!F<^9
R/l/GNm
public String getSSiteURL() \ \gAa-}:
{ -d^c!Iu|
return sSiteURL; p$a+?5'Q
} lf_q6y
p_CCKU
M2LW[z
public void setSSiteURL(String value) yZ,S$tSR
{ {VKP&{~O
sSiteURL = value; "89L^I
} ESnir6HoU
>w#&fd
%FLe@.Ep{D
public String getSFilePath() bpdluWS+)
{ rN`-ak
return sFilePath; Vw5Pgtx
} AA[?a
K[i&!Z&
<"nF`'olV
public void setSFilePath(String value) (>`S{L C>s
{ ]s`cn}d
sFilePath = value; j<}y(~
} 8?h&FbmB
I36ClOG
q0(-"}2l
public String getSFileName() -*W\$P
{ '3 JVUHn
return sFileName; Iy Vmz'
} lQG;WVqW
C5=m~
[S?`OF12
public void setSFileName(String value) Og?P5&C"9D
{ 56H~MnX
sFileName = value; oWBjPsQ
} 0r]-Ltvl?}
s"(F({J
D'Uv7Mis
public int getNSplitter() |v:fP;zc
{ !jRs5{n^Ol
return nSplitter; [>|6qY$D
} Zz!yv(e)H
,<U
U[NQ"
public void setNSplitter(int nCount) __[bKd.
{ _m3#g1m{
nSplitter = nCount; fT5vO.a
} 8^hbS%s!
} 0">9n9
s(y=u>
Q'0:k{G
/* B0,C!??5
**Utility.java +d=8/3O%
*/ Y 9@ 2d
package NetFox; XRXQ 7\n
K.42 VM)F
J['i
public class Utility { Xe@:Aun
ab>>W!r@!
LNF|mS\+D
public Utility() 7|X.E
{ 4']eJ==OH
7&1dr
=qS\+
} ,AyQCUz{*?
B4w/cIj_
//线程睡眠 L+.-aB2!d
public static void sleep(int nSecond) p s_o:*$l
{ 7:n OAN}%
try{ ~Q+J1S]Fs
Thread.sleep(nSecond); @%I-15Jz
} _o{w<b&
catch(Exception e) rM)#}eZK!
{ wPr!.:MF
e.printStackTrace (); 5N$O
} < [q{0,
} sH :_sOV*
fPab%>/T{
//日志 @MfZP~T+
public static void log(String sMsg) ML:H\
{ !0Eo9bU%@
System.err.println(sMsg); Qp~3DUM
} /8LTM|(
SFVqUg3"Z
E$s?)
public static void log(int sMsg) A<[BR*n
{ 5XinZ~
System.err.println(sMsg); >44,Dp]
} 8WLBq-]G
} @c;:D`\p1C
R&MetQ~-{
l*+9R
/* Jv59zI
**TestMethod.java zUz j F
*/ %dq|)r
package NetFox; *q0vp^?
U2*kuP+n
)CG,Udu
public class TestMethod { oZw#]Q@
>"pHk@AWK
e{}vT$-
public TestMethod() r%xf=};
{ ///xx/weblogic60b2_win.exe #>O+!IH
try{ >5j&Q#Bu
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f|&,SI?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [*d<LAnuWP
SiteFileFetch fileFetch = new SiteFileFetch(bean); NkYC(;g
fileFetch.start(); 2t:CK
} husk\
catch(Exception e){e.printStackTrace ();} q82yh&
o*:D/"gb
b$=c(@]
} -02.n}u>
sQ8kLS_q8
mC./,a[
public static void main(String[] args) +/!y#&C&*
{ }cERCS\t
new TestMethod(); `0Xs!f
} =4LyE6
} [*^rH:
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