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)); P:D@5
} qZQB"Q.*
for(int i=0;i<nEndPos.length-1;i++) *^[m?3"W
{ @yV.Yx"p_
nEndPos = nStartPos[i+1]; Yr!@pHy
} )R %>g-dw
nEndPos[nEndPos.length-1] = nFileLength; B ]*v{?<W
} T{WJf-pI
} ZkWX4?&OMt
JG^fu*K
$-^ ;Jl
//启动子线程 LV}Z[\?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; VT ikLuH
for(int i=0;i<nStartPos.length;i++) ;]gj:6M
{ ycD.X"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9 +1}8"~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e^!>W %.7Z
nStartPos,nEndPos,i); uwI$t[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s!73To}>
fileSplitterFetch.start(); I{nrOb1G(
} q,;8Ka )
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !2=m |,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); GN1Q\8)o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %Z~0vwY
nEndPos = " + nFileLength); >o/+z18x
// fileSplitterFetch[nPos.length-1].start(); B`<a~V
`@<>"ff#F
y@XE! L
//等待子线程结束 9U]3B)h%m
//int count = 0; TmviYP gb
//是否结束while循环 (V(8E%<c
boolean breakWhile = false; G^1 5V'*
G/ sRiwL
ol3].0Vc]
while(!bStop) =w!>/#U
{ !)r1zSY"g
write_nPos(); pNFVa<D
Utility.sleep(500); uKA-<nM._c
breakWhile = true; F ?N+ __o
_ASyGmO{
.n\j<Kq
for(int i=0;i<nStartPos.length;i++) 7&`Yl[G
{ c`Q#4e]%_
if(!fileSplitterFetch.bDownOver) %2@O,uCo@
{ ?3#L?Cq
breakWhile = false; $G<!+^T
break; }Y~<|vZ
} ,DL%oQR
} qtR/K=^i
if(breakWhile) )U|0vr8:
break; ~o8
R4_BP5+
dDrzO*a\
//count++; W?H-Ng3E
//if(count>4) f7_V ]
// siteStop(); |S6L[Uo
} Au10]b
n@=D,'cn
XpH d"(*
System.err.println("文件下载结束！"); ]mR!-Fqj
} mI>=S
catch(Exception e){e.printStackTrace ();} 'w"hG$".
} Xk>YiV",?
> I>=/i^
)z\ 73|w
//获得文件长度 he!Uq%e
public long getFileSize() 'ZFbyt Q2
{ c BcZ@e;
int nFileLength = -1; @ JfQ}`
try{ 'O^<i`8U]
URL url = new URL(siteInfoBean.getSSiteURL()); b3.}m[]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?Gnx!3Q
httpConnection.setRequestProperty("User-Agent","NetFox"); i'YM9*yN
+/>XOY|Ie
P>nz8NRq
int responseCode=httpConnection.getResponseCode(); !sVW0JSh
if(responseCode>=400) nPR*mbW
{ itmFZZh
processErrorCode(responseCode); wiP )"g.t
return -2; //-2 represent access is error h+DK .$
} c#zx" ,K
4+B&/}FDLo
tk\)]kj
String sHeader; ;9;jUQ]MyG
PfN[)s4F{R
gP2<L5&Z,
for(int i=1;;i++) O0_kLH$.
{ /l` "@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); TCI)L}L|
//Utility.log(in.readLine()); /?%1;s:'
sHeader=httpConnection.getHeaderFieldKey(i); *v#Z/RrrA
if(sHeader!=null) {d '>J<Da
{ &BxZ}JH=k
if(sHeader.equals("Content-Length")) je;|zfe]
{ \R[f< K%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,1 ^IFBJ
break; K3^2;j1F Q
} *&BS[0;
} X:JU#sI
else rVM?[_'O
break; *J3Z.fq%:i
} 'FM_5`&
} 2l}H=DZV
catch(IOException e){e.printStackTrace ();} Oj1B @QE
catch(Exception e){e.printStackTrace ();} r7+Ytr
G%MdZg&i
MlV3qM@
Utility.log(nFileLength); B=)tq.Q7
R4%}IT^%P
)mu[ye"p
return nFileLength; ('6sW/F*ab
} H;N6X y*~
=X3Rk)2r
|"+UCAU
//保存下载信息（文件指针位置） 2O(= 2X
private void write_nPos() z9 $1jC
{ b *Ca*!
try{ |xFSGrC
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]D<3yIGS
output.writeInt(nStartPos.length); J'C%
for(int i=0;i<nStartPos.length;i++) }k0B
{ bScW<DZJ-
// output.writeLong(nPos); /s Bs eI
output.writeLong(fileSplitterFetch.nStartPos); XP(fWRT1
output.writeLong(fileSplitterFetch.nEndPos); \:jJ{bl^A
} bL2b^UB~%
output.close(); -Mzm~@_s]
} ,In}be$:
catch(IOException e){e.printStackTrace ();} <O3,b:vw
catch(Exception e){e.printStackTrace ();} WesEZ\V
} hQ}y(2A.XI
TG6E^3a P
^wD@)Dz
//读取保存的下载信息（文件指针位置） RG6U~o1
private void read_nPos() M.K%;j`
{ ;Dp<|n
try{ r*g<A2g%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,&LGAa
int nCount = input.readInt(); jJ3dZ<#
nStartPos = new long[nCount]; Q\pI\]p:
nEndPos = new long[nCount]; Z$y~:bz
for(int i=0;i<nStartPos.length;i++) $O9,Gvnxx
{ aucG|}B
nStartPos = input.readLong(); % U|4%P
nEndPos = input.readLong(); >JHQA1mX
} )\+1*R|H}
input.close(); yDw#V`Y^M
} ;:aCZ8e
catch(IOException e){e.printStackTrace ();} #@:GLmD%
catch(Exception e){e.printStackTrace ();} j4+kL4M@H
} (%)<jg1
<P_B|Y4N/
LLPbZ9q
private void processErrorCode(int nErrorCode) ?sclOOh
{ v5 I}a7
System.err.println("Error Code : " + nErrorCode); P( 1Z
} ;v m$F251
[&+5E1%L
S8Yti
//停止文件下载 vt(cC))
public void siteStop() EttQ<z_T
{ eT@,QA(3
bStop = true; k? !'OHmBL
for(int i=0;i<nStartPos.length;i++) )KKmV6>b
fileSplitterFetch.splitterStop(); B`?5G\7L
v4VP7h6uD)
Fjw+D1q.
} Y(R .e7]
} lj 2OOU{
//负责部分文件的抓取 K2D, *w
**FileSplitterFetch.java =6xxZy[
*/ wY*tq{7
package NetFox; f5,!,]XO
sh;>6xB
dPmNX-'7
import java.io.*; %<h+_(\h
import java.net.*; wqAj=1M\
7i88iT
Q6hWHfS
public class FileSplitterFetch extends Thread { ;` !j~
i|CAN,'
wqA7_ -
String sURL; //File URL J'@`+veE
long nStartPos; //File Snippet Start Position ,rWej;CzN
long nEndPos; //File Snippet End Position ,XYtoZa
int nThreadID; //Thread's ID 2!";?E
boolean bDownOver = false; //Downing is over "U*6?]f
boolean bStop = false; //Stop identical lH"4"r
FileAccessI fileAccessI = null; //File Access interface #_'| TT>p#
'<Jqp7$dL
aUbmEHFTV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *V?p&/>MT
{ 1Ts$kdO
this.sURL = sURL; \kG;T=H
this.nStartPos = nStart; ?K= X[
this.nEndPos = nEnd; BL H~`N3U
nThreadID = id; wD5fm5r=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |WsB0R
} tQIa6c4|
yc.9CTxx
ab^>_xD<
public void run() $m;DwlM
{ ~ }?*v}
while(nStartPos < nEndPos && !bStop) X^)vZL?
{ `-[|@QNFz
YxWA] yL
|%12Vr]J
try{ 0tEe $9eK@
URL url = new URL(sURL); XG01g3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @Q%<~b[y
httpConnection.setRequestProperty("User-Agent","NetFox"); (!0fmL
String sProperty = "bytes="+nStartPos+"-"; tl^![Z
httpConnection.setRequestProperty("RANGE",sProperty); y28 e=i
Utility.log(sProperty); Rp_)LA
!+T29QYK8
~'#,*kA:6
InputStream input = httpConnection.getInputStream(); =k:yBswi
//logResponseHead(httpConnection); lFbf9s:$B
Jq_AR!} %
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byte[] b = new byte[1024]; <L+y 6B
int nRead; evGUl~</~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >6A8+=
{ 48RSuH
nStartPos += fileAccessI.write(b,0,nRead); zaG1
//if(nThreadID == 1) Q8^g WBc
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C!}t6
} 6Ej.X)~'K
< m/@_"
KYR64[1
Utility.log("Thread " + nThreadID + " is over!"); :Hq#co
bDownOver = true; `w EAU7m:
//nPos = fileAccessI.write (b,0,nRead); Z Z9D6+R
} 9;R'Xo=y
catch(Exception e){e.printStackTrace ();} `}S;_g!
} H,0Io
} Xsd+5="{N
u:M)JG
XxLauJP K
//打印回应的头信息 Y|~+bKa
public void logResponseHead(HttpURLConnection con) D"8?4+
{ kn&>4/')
for(int i=1;;i++) T1i}D"H %
{ +{au$v}
String header=con.getHeaderFieldKey(i); I8Q!`KJ
if(header!=null) oe,yCdPs
//responseHeaders.put(header,httpConnection.getHeaderField(header)); '|@?R|i0
Utility.log(header+" : "+con.getHeaderField(header)); $$e"[g
else lky5%H
break; M6XpauR-
} \`Ow)t:
} T':} p2}w+
!U4<4<+
jP}Ix8vc=
public void splitterStop() DE!c+s_g4
{ }fh<LCwTi
bStop = true; q6EZ?bo{
} THY=8&x)
s5J?,xu
GGez!?E%
} 4x|\xg( l
4KB>O)YNg'
W[t0hbVw
/* 1h#e-Oyff
**FileAccess.java Sc9}WU
*//文件访问(定位，写) bPVQ-
package NetFox; *u]aWx
import java.io.*; >,a$)z
.> 5[;
GBYwS{4
public class FileAccessI implements Serializable{ ):7mK03J
'q\[aKEX=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vJ{aBx`VS
RandomAccessFile oSavedFile; h?P- :E
long nPos; GUC.t7!
^T*'B-`C7X
9wdl1QS
public FileAccessI() throws IOException |vtj0,[
{ wyB
this("",0); $[V-M\q
} 2Z+:^5
*9tRhRc
*;[g Ga~
public FileAccessI(String sName,long nPos) throws IOException (O"-6`w[
{ ^NXxMC(e+
oSavedFile = new RandomAccessFile(sName,"rw"); 6h?)x
this.nPos = nPos; +;bP.[Z
oSavedFile.seek(nPos); {<Y\flj{@m
} )4^Sz&\
$7*@TMX
R?HuDxHk
public synchronized int write(byte[] b,int nStart,int nLen) eXi}-~o
{ 4(&sw<k
int n = -1; "2Q*-
try{ p|Qn?^C:
oSavedFile.write(b,nStart,nLen); ?H!QV;ku
n = nLen; e[Jh7r>'
} ..Bf-)w
catch(IOException e) _*++xF1
{ th%T(D5n
e.printStackTrace (); Wo{4*~f
} [Gc9 3PA7q
ZoR6f\2M
{ t@7r
return n; 6[Wv g
} DLO2$d
Ie(M9QMp
+}iuTqu5
} 6"yIk4u:
v]y=+* A
y wmC>`0p
/* [:8+ +#KD
**SiteInfoBean.java ),XDY_9K
*/ 7X<#
package NetFox; Y'yGhpT~
;%Kh~
;]>a7o
public class SiteInfoBean { 7M<co,"
C(n_*8{
cUr5x8<W).
private String sSiteURL; //Site's URL ZMGC@4^F
private String sFilePath; //Saved File's Path gWfMUl
private String sFileName; //Saved File's Name pkc*toW
private int nSplitter; //Count of Splited Downloading File g`dAj4B
W1ql[DqE{
bMGXx>x
public SiteInfoBean() yH0vESgv
{//nSplitter的缺省值为5 S]?I7_
//default value of nSplitter is 5 gwDVWhq
this("","","",5); jD?*sd
} dH)\zCt
IHv>V9yiG
t:YMF$Z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KM/c^a4V
{ OlM3G^1e1
sSiteURL= sURL; lJt?0;gn
sFilePath = sPath; WmuYHEU
sFileName = sName; 4VhKV JX
this.nSplitter = nSpiltter; QBjvbWoIG(
(Q"~bP{F
>cH}sNHy
} vf-8DB
]Xg7XY
7n7UL0Oc1
public String getSSiteURL() Z6#(83G4
{ 4A)_D{(SH
return sSiteURL; Q+*@!s
} KebC$g@W
"Ug+#;}p$
7MIrrhk
public void setSSiteURL(String value) +iw4>0pi
{ o\X|\nUk
sSiteURL = value; x{S2
} ,zh_-2^X
T:g%b @
hbm#H7Y
public String getSFilePath() d(C5i8d
{ e6Kyu*
return sFilePath; QObHW[:F
} (3&P8ZGNR
x5b .^75p$
))I[@D1b
public void setSFilePath(String value) akzKX}
{ !:a^f2^=
sFilePath = value; m2[J5n?zLL
} JvYs6u
AE=E"l1]
@[bFlqsE
public String getSFileName() |}Z2YDwO/
{ e?:1wU
return sFileName; WQsu}_g5y
} .f`KP!p.
T>w;M?`9K
8Yf=)
public void setSFileName(String value) cC9haxW
{ DK1{Z;Z
sFileName = value; %rO)w?
} E+J+fi
(?ZS9&y}
Tj6kCB
public int getNSplitter() p5J!j I=
{ 95Q^7oI
return nSplitter; ,3Nna:~f
} ?;ZnD(4?
$`<-;kI
!*o{xq
public void setNSplitter(int nCount) {}P~nP
{ w`[`:H_z
nSplitter = nCount; 5Q,j+
} 9>;CvR
} &t}6sD9o
&}d5'IRT
f<>CSjQ4c
/* fzUG1|$e
**Utility.java Nb)Mh
*/ ( ;_AP.
package NetFox; ie7P^:T|+
Nt687
dg&GMo
public class Utility { S2EV[K8#
o0TB>DX$`
0@RVM|
public Utility() L$ZsNs+
{ w@H@[x
iyr<qtwK
U "v=XK)!
} M|7][!<G!
U5[r&Y D
//线程睡眠 |{La@X
public static void sleep(int nSecond) `t+;[G>ZE
{ FBa-gm<9
try{ L$^)QxH7
Thread.sleep(nSecond); >J{e_C2ZS
} zICrp
catch(Exception e) zb.sh
{ S 9;FD3
e.printStackTrace (); Bnw^W_
} )lP(isFP
} Z<'iT%6+r
H=9{|%iS
//日志 l@`n4U.Gwl
public static void log(String sMsg) {dlG3P='`f
{ q><wzCnRu~
System.err.println(sMsg); ;A0ZcgF
} (O/W`qo
oSl}A,aQ(
[d=BN ,?
public static void log(int sMsg) |}@teN^J*U
{ qNUd "%S
System.err.println(sMsg); VH] <o0
} O6ltGtF
} +pe\9F
? 3oUkGfn
J)sOne
/* 79B+8= K
**TestMethod.java .e\PCf9v
*/ lDVgW}o@
package NetFox; ^G "Qp8 "
p4P"U
MRzY<MD
public class TestMethod { yO@@-)$[y
&D&U!3~(
HcpAp]L)
public TestMethod() $5@[l5cJU;
{ ///xx/weblogic60b2_win.exe HC"yC;_
try{ $|VdGRZ1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qR kPl!5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K{XE|g
SiteFileFetch fileFetch = new SiteFileFetch(bean); Mtn{63cK
fileFetch.start(); [@NW
} Fe2t[y:8h
catch(Exception e){e.printStackTrace ();} ;8cTy8
ek d[|g
f||S?ns_
} ~|ha91
wdIJ?\/763
rj/nn)vv;
public static void main(String[] args) 31N5dIi,
{ fn8|@)J
new TestMethod(); Q)5V3Q]@^
} 'fZ\uMdTx
} hJ?PV@xy
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