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)); 5d%_Wb'
} 8F\~Wz7K
for(int i=0;i<nEndPos.length-1;i++) m'3OGvd
{ [#7D~Lx/
nEndPos = nStartPos[i+1]; F68},N>vr@
} ruzMag)
nEndPos[nEndPos.length-1] = nFileLength; "-28[a3q
} T\)dt?Tv#\
} 5"$e=y/
~37R0`C
ypgliq(
//启动子线程 IN<:P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >G<4Ro"
for(int i=0;i<nStartPos.length;i++) f_~}X#._
{ =obt"K%n
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PIgGXNo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3,%nkW
nStartPos,nEndPos,i); 9)jo7,VM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @>+^W&
fileSplitterFetch.start(); ,n^TN{#
} YfV"_G.ad|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sN"p5p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;tXB46
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]!]`~ Z/
nEndPos = " + nFileLength); q|R+x7x
// fileSplitterFetch[nPos.length-1].start(); ^8b~ZX
$xLEA\s
e',hC0&S
//等待子线程结束 4u@yJ?U
//int count = 0; (6e!09P&
//是否结束while循环 =VCi8jDkP
boolean breakWhile = false; /]pX8 d
mgk64}K[n
+[>yO _}
while(!bStop) jG =(w4+
{ A1mYkG)l
write_nPos(); f&=K]:WDe
Utility.sleep(500); <m~T>Ql1
breakWhile = true; MP6 \r
@=02
x&QNP
for(int i=0;i<nStartPos.length;i++) /;zZnF\e
{ <+ -V5O^
if(!fileSplitterFetch.bDownOver) 7^n,Tig
{ &*X3ch
breakWhile = false; (PRaiE
break; s4!|v`+$M
} nrxjN(9V%+
} cZPbD;e:
if(breakWhile) cjCE3V9X
break; zG&WWc`K
ztRWIkI q
rd|@*^k
//count++; bv.EM
//if(count>4) Rh!L'?C
// siteStop(); emGV]A%nss
} ;:v]NZtc
$ iX^p4v
oc!biE`u
System.err.println("文件下载结束！"); #N<s^KYG-
} }T?i%l
catch(Exception e){e.printStackTrace ();} ;m-6.AV
} Ej;Vr~Wi
##SLwrg
*5ka.=Qs
//获得文件长度 @C!JtgO%
public long getFileSize() }`+O$0A
{ dL1~]Z y
int nFileLength = -1; _Ym&UY.u#
try{ *O"%tp6
URL url = new URL(siteInfoBean.getSSiteURL()); ^G]KE8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M>`?m L
httpConnection.setRequestProperty("User-Agent","NetFox"); DR.3 J`?K
nEjo,
Z\ "Kd
int responseCode=httpConnection.getResponseCode(); 3MS3O.0]/
if(responseCode>=400) j<. <S {
{ 7AZ5%o
processErrorCode(responseCode); 6Y0/i,d*
return -2; //-2 represent access is error &xPOp$Sx~
} `XQx$I
O[i2A(
Y?"v2~;3
String sHeader; |[lxV&SD.
KUl Zk^a
, V0iMq
for(int i=1;;i++) $ioaunQKP
{ TMnT#ypf<5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); umq$4}T'$
//Utility.log(in.readLine()); z{ Zimr
sHeader=httpConnection.getHeaderFieldKey(i); !?tu! M<1?
if(sHeader!=null) $i1>?pb3
{ Hl4vLx@
if(sHeader.equals("Content-Length")) &F@tmM~
{ '=@-aVp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _*OaiEL+:
break; *@b~f&Lx6
} "6|'&6&
} 7v4-hfN
else Jgi{7J
break; ex;Yn{4
} s+OvS9et_
} NKIkd
catch(IOException e){e.printStackTrace ();} .HH,l
catch(Exception e){e.printStackTrace ();} S4@117z5
~|$) 1
\kua9bK
Utility.log(nFileLength); $S"zxEJJ Y
LN,$P
4nVO.Ud0$X
return nFileLength; (_s!,QUe
} gn;nS{A
W2X+NacD
@n~ND).
//保存下载信息（文件指针位置） r&j+;JM5
private void write_nPos() iG;d0>Sp
{ 9I^H)~S
try{ S%a}ip&
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9v5.4a}
output.writeInt(nStartPos.length); n]6w)wE(
for(int i=0;i<nStartPos.length;i++) gvwCoCbb
{ N8/Au=De_
// output.writeLong(nPos); Ed ?Yk* 4
output.writeLong(fileSplitterFetch.nStartPos); |?pYJkrYO
output.writeLong(fileSplitterFetch.nEndPos); <7RkM
} l")o!N?
output.close(); Nt,]00S\w
} Q>+_W2~]
catch(IOException e){e.printStackTrace ();} :">~(Rd ZH
catch(Exception e){e.printStackTrace ();} *I;Mp
} s>"WQ|;6
<)0LwkFtB
4^jZv$l5
//读取保存的下载信息（文件指针位置） plz=G}Y
private void read_nPos() XQJV.SVS
{ }gi`?58J6
try{ @Z1?t%1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ua.6?W)
int nCount = input.readInt(); H~1?MAX
nStartPos = new long[nCount]; ./5MsHfbxt
nEndPos = new long[nCount]; sB*h`vs0T
for(int i=0;i<nStartPos.length;i++) JqH.QnKcv
{ u0$5Fd&X
nStartPos = input.readLong(); Hf E;$
nEndPos = input.readLong(); ;*85'WcS
} S+E3;' H
input.close(); hGaYQgGq
} (vYf?+Kb
catch(IOException e){e.printStackTrace ();} k?@W/}Iv9
catch(Exception e){e.printStackTrace ();} a}+_Yo(Q
} aX%g+6t2
:;gwdZ
EZNB`gO
private void processErrorCode(int nErrorCode) 8)Bn?6.
{ s#8{:ko
System.err.println("Error Code : " + nErrorCode); s\K-(`j}
} Snvj9Nr
"MVN/Gl
DQHGq_unP
//停止文件下载 T=)L5Vuq<
public void siteStop() %@,:RA\pm
{ >+W?!9[p:2
bStop = true; q=i,'.nS
for(int i=0;i<nStartPos.length;i++) h11bK'TIv
fileSplitterFetch.splitterStop(); f<xt3
@o-evH;G
~NJLS-
} /(}l[jf
} kQ:>j.^e
//负责部分文件的抓取 E<.{ v\
**FileSplitterFetch.java JjL0/&
*/ 61 HqBa
package NetFox; =F;^^VX
tZ6v@W
!&<Wc^PG
import java.io.*; F^[Rwzv>c
import java.net.*; Ub-k<]yZ
,jdKcWy'
bgx5{!A
public class FileSplitterFetch extends Thread { _M[[o5{
(>/Dw|,m
r;s3(@[,@
String sURL; //File URL )Z`viT
long nStartPos; //File Snippet Start Position .~/;v~bL
long nEndPos; //File Snippet End Position }N=zn7W
int nThreadID; //Thread's ID I5AjEp
boolean bDownOver = false; //Downing is over jq]\oY8y
boolean bStop = false; //Stop identical ]{l O
FileAccessI fileAccessI = null; //File Access interface ;Q%19f3,6
ckkM)|kK
pRfHbPV?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Wn)A/Z ^r
{ .m % x-i
this.sURL = sURL; N_~Wu
this.nStartPos = nStart; q.Aw!]:!
this.nEndPos = nEnd; Nl>b'G96
nThreadID = id; 7B>cmi
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pLFL6\{g
} @;-Un/'C;7
{s^n|b}
So0,)
public void run() W!Os ci
{ oI"Fpo
while(nStartPos < nEndPos && !bStop) SX<>6vH&
{ N,'qMoNf
(]uoN4
;{#M
try{ /t2<OU9
URL url = new URL(sURL); 4rCqN.J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e2H'uMy;&
httpConnection.setRequestProperty("User-Agent","NetFox"); XT;IEZQZ
String sProperty = "bytes="+nStartPos+"-"; 7UnO/K7oB.
httpConnection.setRequestProperty("RANGE",sProperty); v?iH}7zb%Q
Utility.log(sProperty); CX(yrP6;
`E%d$
x[<#mt
InputStream input = httpConnection.getInputStream(); ^.aEKr
//logResponseHead(httpConnection); Ib<+m%Ac
<UHf7:0V
kT3;%D^
byte[] b = new byte[1024]; iY`7\/H!L
int nRead; =(uy':Dbn*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1 jd=R7
{ 9U%}"uE
nStartPos += fileAccessI.write(b,0,nRead); BJ;cF"Kp
//if(nThreadID == 1) |zegnq~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !)1Zp*
} >@\?\!Go
e(5Px!B
^C#bW<T
Utility.log("Thread " + nThreadID + " is over!"); dEl3?~
bDownOver = true; fpC@3itI
//nPos = fileAccessI.write (b,0,nRead); v8M#%QoA
} m(Xr5hw:6
catch(Exception e){e.printStackTrace ();} &_TjRj"
} Q#AHEm{9;s
} M(gWd8?#
l3 Bc g
iK23`@&%_
//打印回应的头信息 Lr]Hvd
public void logResponseHead(HttpURLConnection con) Jywz27j
{ Ho*RLVI0U
for(int i=1;;i++) Aba%Gh
{ \{^yB4F_Z
String header=con.getHeaderFieldKey(i); ?DTP-#5Ba
if(header!=null) h1d0{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); bao5^t}
Utility.log(header+" : "+con.getHeaderField(header)); 23?0'AU
else PW\FcT
break; V)?g4M3}
} i(#c Yb
} rm;"98~zJ?
, X+(wp
ed2&9E>9b
public void splitterStop() x@l~*6!K
{ YZ+g<HXB
bStop = true; $CV'p/^En
} V&nJT~k
HBYpjxh
ho=]'MS|
} {:j!@w3
d|HM
f@X*Tlx^|
/* qOanu
**FileAccess.java 9`VF [* 9
*//文件访问(定位，写) VZ!$'??
package NetFox; u$^`hzfI
import java.io.*; =5#Jsn?U
?Gu>!7
*g}&&$b0
public class FileAccessI implements Serializable{ $+N^ s^
S :|*wB
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U6 R4UK
RandomAccessFile oSavedFile; L-TVe
long nPos; 'Z9F0l"Nr
Y3&ecEE
F'Vl\qPt
public FileAccessI() throws IOException sM_e_e
{ oVgNG!/c0
this("",0); }# ^PbM
} y=`(`|YW}`
2$UR"P
@=1``z#
public FileAccessI(String sName,long nPos) throws IOException }Elce}
{ cW%O-
oSavedFile = new RandomAccessFile(sName,"rw"); jg/<"/E
this.nPos = nPos; .k(_j.v
oSavedFile.seek(nPos); md s\~l73
} `v er "s;
{bEEQCweNJ
| Ylk`<
public synchronized int write(byte[] b,int nStart,int nLen) ZJm^znpw6
{ "xI[4~'`:
int n = -1; ,6L>f.V^(U
try{ |g!# \
oSavedFile.write(b,nStart,nLen); ~(S4/d5
n = nLen; G-<~I#k
} aC` c^'5
catch(IOException e) vRs5-T
{ m$g^On
e.printStackTrace (); C_)>VPD
} iB-s*b<`~
K>eG5tt
#+\G- =-
return n; 9mm(?O~'p
} `7ZJB$7D|*
'& :"/4@)
gV;GC{pY
} '+wTrW m~j
tsD^8~ t|h
55\mQ|.Jn
/* .@V>p6MV
**SiteInfoBean.java B:.rp.1
*/ aQFHB!
package NetFox; p-kqX
-GjJrYOU
S\(_"xJPp
public class SiteInfoBean { N|}`p"
aoS1Yt'@
r0>T7yPAK
private String sSiteURL; //Site's URL 3\7$)p+c
private String sFilePath; //Saved File's Path qiN'Tuw9
private String sFileName; //Saved File's Name z(qz(`eGC&
private int nSplitter; //Count of Splited Downloading File ?CDq^)T[
q4oZJ-`
,,gYU_V
public SiteInfoBean() !NjE5USi
{//nSplitter的缺省值为5 Y}Uw7\e
//default value of nSplitter is 5 x ,W+:l9~s
this("","","",5); sn%fE
} kF .b)
70eN]OY
:Ib\v88WIv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) d\M !o*U
{ jK53-tF~I
sSiteURL= sURL; ;*p}~#2
sFilePath = sPath; Q{60^vg
sFileName = sName; 7j8_O@_
this.nSplitter = nSpiltter; ;q2T*4NN
6~LpBlb
Ok!{2$P8U9
} &@+;]t
)3
@T"385>
public String getSSiteURL() bv"S(
{ DP_\%(A
return sSiteURL; jYv !}
} vCM'nkXY
1YxI q565
/_\4(vvf
public void setSSiteURL(String value) /Y:Zqk3
{ HFOp4
sSiteURL = value; ^Tx1y[hw$
} Z/x~:u_
bkTj Q
ojri~erJE?
public String getSFilePath() lRb)Tz6SE
{ |a+8-@-Tj
return sFilePath; 26A#X
} R#>E{[9
"5Mo%cUp
z~qQ@u|
public void setSFilePath(String value) Qw:j2g2H7
{ KMV!Hqkk
sFilePath = value; O9Aooe4W=
} \=)h6AG
r+Y1m\
x{E[qH_1Fm
public String getSFileName() x/~M=][tN
{ 3-'|hb
return sFileName; rGs> {-T3
} 7+"X^$
U N/.T
DVd/OU
public void setSFileName(String value) X9R-GT
{ ~$B,K]
sFileName = value; Iu8=[F>
} P1<;:!8'
.JE7vPv%!
M%/D:0
public int getNSplitter() Ts\7)6|F
{ 6C:Lq%}
return nSplitter; >qCT#TY
} 0Ko,S(M_
TR|; /yJ
l-&f81W
public void setNSplitter(int nCount) -nW-I\d%
{ 7_RU*U^
nSplitter = nCount; :.<&Y=^
} (_* a4xGF
} ag6S"IXh
7j+.H/2
t%)L8%Jr
/* vzL>ZBeZ
**Utility.java kQ +
*/ ]zO]*d=m
package NetFox; g!$ "CX%8
bpkn[K"(
99 ["I:
public class Utility { ;$Y?j8g
04s N4C
f5N~K>
public Utility() f: Rh9
{ *M{1RMc
hRP0Djc
,#crtX
} A)xI.Q6
.+y#7-#6
//线程睡眠 zMa`olTZ
public static void sleep(int nSecond) `F)Iv:;y,
{ [f'7/w+
try{ =Zj9F1E[i
Thread.sleep(nSecond); wdg[pt />
} 1||e!W
catch(Exception e) V1ug.Jv^
{ @wo9;DW`
e.printStackTrace (); &c]x;#-y
} ;j$84o{
} *q^'%'
!MbRI
//日志 $z<CkMP!U7
public static void log(String sMsg) og>f1NwS[
{ bHp|>g
System.err.println(sMsg); 9DIGK\
} L8V'mUyD
CTwP{[%Pk
KT3[{lr
public static void log(int sMsg) `]%{0 Rx
{ ^3el-dZ
System.err.println(sMsg); O&}07(
} As"'KR
} +/ #J]v-
cJt#8P
rTi.k
/* ^#G>P0mG%
**TestMethod.java (vY10W{
*/ L9x,G!
package NetFox; `q F:rQ
lU\|F5O@#
qB8<(vBP+
public class TestMethod { %hXa5}JL
a(m#GES
j#-74{Y$ J
public TestMethod() |_O1V{Q=
{ ///xx/weblogic60b2_win.exe n44j]+P
try{ C ZJW`c/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5f1yszd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zP5HTEz
SiteFileFetch fileFetch = new SiteFileFetch(bean); rIu>JyC"p
fileFetch.start(); \\[P^ tsF
} Ar|_UV>Zf
catch(Exception e){e.printStackTrace ();} Wjj'yqBO^
}b1P!xb!A
$Q?UyEi
} Lg'z%pi
c0tv!PSw
uz%rWN`{
public static void main(String[] args) &)rmv
{ 3iY`kf
new TestMethod(); M,l Ib9
} b+w|3bQa
} 5Eq_L
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