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)); ErmlM#u
} ;zk& 7P0
for(int i=0;i<nEndPos.length-1;i++) [vCZoG8+>
{ k'Is]=3
nEndPos = nStartPos[i+1]; vJTdZ p
} ^ z!g3
nEndPos[nEndPos.length-1] = nFileLength; xe9E</M_
} SbS*z:
} VrDSN
~.\CG'g
u*LMpTnn
//启动子线程 ;>YLL}]j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b?S,%
for(int i=0;i<nStartPos.length;i++) x UM,"+h
{ OI:G~Wg
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?Vg251-H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jNRR=0
nStartPos,nEndPos,i); RN2^=$'.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HoE@t-S
fileSplitterFetch.start(); 5eS0 B{,c
} {yFCGCs
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %@Mv-A6)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v;_m1UpuW
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (SMnYh4
nEndPos = " + nFileLength); zM:&`6;e
// fileSplitterFetch[nPos.length-1].start(); ]34fG3D|
kF{'?R5w
I_ O8 9Sgn
//等待子线程结束 ^\o3V<
//int count = 0; {"f4oK{w
//是否结束while循环 ppL*#/jYt
boolean breakWhile = false; r2dU>U*:4
[\|`C4@3a
k2]fUP
while(!bStop) va6e]p*Oy
{ r:rM~``
write_nPos(); i3 ?cL4
Utility.sleep(500); n[|*[II
breakWhile = true; K,B qVu
S)`%clN}J
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for(int i=0;i<nStartPos.length;i++) I$yFCdXr
{ l=+hs
if(!fileSplitterFetch.bDownOver) #GoZH?MAF
{ 7S^ba
breakWhile = false; wg-qq4Q\
break; OGA_3|[S
} .AHf]X0
} ')G,+d^
if(breakWhile) =17d7#-
break; 0<ze'FbV]
04o>POR
K14FY2"
//count++; jg)+]r/hS
//if(count>4) 3:H[S_q
// siteStop(); Mk=M)d`
} r1pj-
{Sl#z}@s
w^BF.Nu
System.err.println("文件下载结束！"); ML:Zm~A1U
} $G UCVxs
catch(Exception e){e.printStackTrace ();} Z|t`}lK
} D^m`&asC
.{\lbI
oh^/)2W
//获得文件长度 ORCG(N
public long getFileSize() 3haR/YN
{ )~> C1<
int nFileLength = -1; )s-[d_g
try{ %?sPKOh3N}
URL url = new URL(siteInfoBean.getSSiteURL()); q7#4e?1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g]$e-X@k
httpConnection.setRequestProperty("User-Agent","NetFox"); +mu.W r
|XGj97#M
S1vUP5cZ
int responseCode=httpConnection.getResponseCode(); NUN~T (
if(responseCode>=400) 5I`_SOa!
{ '?gF9:
processErrorCode(responseCode); Qq7%{`<}
return -2; //-2 represent access is error ]?un'$%e
} fpPB_P{Ua
tZL|;K
#B$r|rqamq
String sHeader; s!g06F
jx=5E6(h
gRsV-qS
for(int i=1;;i++) hD*83_S
{ w%2|Po5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .`ZuUr
//Utility.log(in.readLine()); @A.7`*i_
sHeader=httpConnection.getHeaderFieldKey(i); uUIjntSF(
if(sHeader!=null) 1#w'<}h#U
{ k00&+C
if(sHeader.equals("Content-Length")) E[=#Rw!*
{ YqQAogyh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O)FkpZc@9c
break; evQk,;pIm
} F!RzF7h1
} IE*5p6IM~
else ~[Fh+t(Y
break; {SRv=g
} Efa3{ 7>{
} fD* ?JzVY
catch(IOException e){e.printStackTrace ();} qx'F9I
catch(Exception e){e.printStackTrace ();} #;(Q \
yDORL| E'
?PSJQ3BC|
Utility.log(nFileLength); Tfytc$aQ
:OKU@l|
7`P1=`..
return nFileLength; s +Q'\?
} UCBx?9O/0
$/)0iL{0
<)]j;Tl
//保存下载信息（文件指针位置） (?vKe5
private void write_nPos() hfL8]d-
{ Qd"R@+i
try{ RD_l
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8mnzxtk
output.writeInt(nStartPos.length); 9O{b8=\}
for(int i=0;i<nStartPos.length;i++) JY0}#FtgV
{ dfR?O#JPU
// output.writeLong(nPos); ?y|8bw<
output.writeLong(fileSplitterFetch.nStartPos); CkeqK
output.writeLong(fileSplitterFetch.nEndPos); H1or,>GoO
} +ab#2~,)
output.close(); 4|INy=<"t
} E]gy5y
catch(IOException e){e.printStackTrace ();} b8O }XB
catch(Exception e){e.printStackTrace ();} 1,Uf-i
} "8R\!i.
_08y; _S
5M= S7B3=
//读取保存的下载信息（文件指针位置） &eIwlynm
private void read_nPos() )J(@e4;Rv
{ Y![//tg
try{ 3FQXp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~E3"s
int nCount = input.readInt(); A4IPd
nStartPos = new long[nCount]; WW3! ,ln_
nEndPos = new long[nCount]; o%3VE8-
for(int i=0;i<nStartPos.length;i++) j\%m6\{n|
{ rhH !-`m
nStartPos = input.readLong(); Sd?+j;/"
nEndPos = input.readLong(); "o>` Y
} 7: .bqRu
input.close(); eCy]ugsi%
} Bc1MKE5
catch(IOException e){e.printStackTrace ();} KKGwMJku}
catch(Exception e){e.printStackTrace ();} JrJTIUf_
} mKZ^FgG
[W--%=Ou
]D\p<4uepM
private void processErrorCode(int nErrorCode) x)prI6YMv\
{ yoVN|5
System.err.println("Error Code : " + nErrorCode); [h@MA|
} NB.&J7v
g6!#n
&aWY{ ?_
//停止文件下载 IfF&QBi
public void siteStop() &Tn7
{ 40Z/;,wp{
bStop = true; *rmwTD"
for(int i=0;i<nStartPos.length;i++) 9 :FzSD
fileSplitterFetch.splitterStop(); uTIl} N
l EsE]f
1IeB_t
} n,o;:c
} idGhWV'
//负责部分文件的抓取 J%ue{PL7
**FileSplitterFetch.java a4D4*=!G0
*/ }< m@82\
package NetFox; hZDv5]V:0
h@D</2>
SX6P>:`
import java.io.*; b1t7/q
import java.net.*; L}.V`v{zc
O\[Td
BGZvgMxLJ
public class FileSplitterFetch extends Thread { jY8u1z
h| ]BA}D
c69M
String sURL; //File URL VsR`y]"g
long nStartPos; //File Snippet Start Position R:FyCT_,
long nEndPos; //File Snippet End Position *l\vqgv.Z
int nThreadID; //Thread's ID %{K6
boolean bDownOver = false; //Downing is over &Vi0.o
boolean bStop = false; //Stop identical sAKQ.8$h*
FileAccessI fileAccessI = null; //File Access interface #Cz6c%yK
ey3;rY1
hXM2B2[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G##^xFx
{ ;WpPdR2
this.sURL = sURL; !Knv/:+
this.nStartPos = nStart; Co^a$K
this.nEndPos = nEnd; ICI8xP}a?
nThreadID = id; y1zep\-D
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ea2&7
} K#],4OG
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KqT~MPl
public void run() 8L}N,6gC4_
{ Zjh9jvsW
while(nStartPos < nEndPos && !bStop) ?FRQ!R
{ 9,;+B8-A
R@H}n3,
~*Ir\wE
try{ NurbioFL
URL url = new URL(sURL); j[o5fr)L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >5!/&D.q
httpConnection.setRequestProperty("User-Agent","NetFox"); J"dp?i
String sProperty = "bytes="+nStartPos+"-"; ;o0o6pF
httpConnection.setRequestProperty("RANGE",sProperty); 7f`x-iH!]7
Utility.log(sProperty); )gAFz+
w_ po47S4
e{x|d?)8
InputStream input = httpConnection.getInputStream(); kg_f;uk+
//logResponseHead(httpConnection); Y)X58_En
r ,,A%
G ]mX+?
byte[] b = new byte[1024]; p3r1lUw
int nRead; f{[,!VG
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \w=7L- 8
{ YJ{d\j
nStartPos += fileAccessI.write(b,0,nRead); 1yIo'i1
//if(nThreadID == 1) .DkDMg1US
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7J%v""\1!
} n!(g<"
Q,A`"e#:
|fk,&5s
Utility.log("Thread " + nThreadID + " is over!"); ]Zf@NY
bDownOver = true; .W+ F<]r
//nPos = fileAccessI.write (b,0,nRead); WPM<Qv L
} i#~1|2
catch(Exception e){e.printStackTrace ();} ~Zd n#z\
} r,4V SyZF\
} tK|hC[
cMEM}Qh T
TIa`cU`
//打印回应的头信息 |KFWW
public void logResponseHead(HttpURLConnection con) \'L6m1UZ%
{ D{,B[5
for(int i=1;;i++) "lf_`4
{ =`X;fz
String header=con.getHeaderFieldKey(i); )LYj,do
if(header!=null) ab 1\nzpd
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &xqe8!FeA
Utility.log(header+" : "+con.getHeaderField(header)); : |c,.uO
else :l>T~&/98
break; ku'%+svD
} XabrX|B#
} b+M[DwPw
5W!E.fz*T
6zLz<p?
public void splitterStop() CW=-@W7
{ EtH)E)
bStop = true; ?mt$c6-
} Ffm Q$>S
| ~G;M*q
LE Y Y{G?
} j$]t`6gG
z~oGd,
Ac.z6]p
/* EVj48
**FileAccess.java I#Tl
*//文件访问(定位，写) Hf %;FaJ=
package NetFox; /d >fp
import java.io.*; fXw%2wg
A?;/]m;
j86s[Dty
public class FileAccessI implements Serializable{ xL>0&R
i*Y/q-N|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 't{=n[
RandomAccessFile oSavedFile; 5Tpn`2F
long nPos; |U^ ff^]
2uWzcy ?F
5Kv=;o=U
public FileAccessI() throws IOException 'EREut,>'
{ h3p 3~xq
this("",0); "eQ96^'J
} !*|CIxk(
y::;e#.
ORx,n7-
public FileAccessI(String sName,long nPos) throws IOException igz:ek`
{ Sjr(e}*
oSavedFile = new RandomAccessFile(sName,"rw"); `bT{E.(T
this.nPos = nPos; HXdPKS4q
oSavedFile.seek(nPos); O|j5ulO}&"
} )hQNIt3o_
i%*x7zjY{
h)wR[N]n
public synchronized int write(byte[] b,int nStart,int nLen) 3<+l.Wly
{ l}(~q!r
int n = -1; O:7y-r0i
try{ 6g$04C3tHi
oSavedFile.write(b,nStart,nLen); ~*B1}#;
n = nLen; z7PPwTBa
} <tF]>(|M
catch(IOException e) T"d]QYJS
{ il-&d]AP
e.printStackTrace (); 5Ll[vBW
} LwGcy1F.
x2ol
RV(}\JU
return n; +Kq>r|;
} h'-TZXs0e1
2|%30i,vV
^1cqx]>E
} Y5MHd>m
}(tGjx]
yJp&A
/* W: ?-d{
**SiteInfoBean.java WejY b;KS
*/ W&!Yprr
package NetFox; >uuX<\cW
C#-x 3d-{
cE*|8'rSf
public class SiteInfoBean { QHs]~Ja
5h> gz
%?wuKZLnc
private String sSiteURL; //Site's URL N{9<Tf*
private String sFilePath; //Saved File's Path 6U/wFT!7$
private String sFileName; //Saved File's Name a|7V{pp=M
private int nSplitter; //Count of Splited Downloading File +u=xBhZ
;C"J5RA
p-7dJ
public SiteInfoBean() v}_$9&|S
{//nSplitter的缺省值为5 f8&=D4)-w
//default value of nSplitter is 5 If&p$pAH?
this("","","",5); C3_*o>8
} {9l4 pT3
`\Npu
|M K-~ep
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v%FVz
{ X&lkA (
sSiteURL= sURL; ,!Hl@(
sFilePath = sPath; #SqOJX~Q
sFileName = sName; u\E.H5u27
this.nSplitter = nSpiltter; 16Xwtn72
]Pd*w`R
1OGlD+f
} NfO0^^"
uyA9`~p=#
#* Hhe>
public String getSSiteURL() gvU6p[D
{ +.R-a+y3
return sSiteURL; 8p211MQ<
} c"z%AzUV'
9/%|#b-z
N4Lk3]
public void setSSiteURL(String value) iK#{#ebAoW
{ aFSZYyPxwv
sSiteURL = value; ,f1wN{P
} e!-'O0-Kw
HIU@m<
|-|BM'Y
public String getSFilePath() A|&EI-In
{ VC+\RB#:-
return sFilePath; ;|^fAc~9{r
} -12v/an]L7
1=D!C lcb
lR(&Wc\j
public void setSFilePath(String value) ?SAi tQ3
{ qQ_B[?+W
sFilePath = value; iBi/9
} UB1/FM4~
W#wM PsB
"Dk:r/
public String getSFileName() 5[R}MhLZ
{ TB[vpTC9)
return sFileName; E7<:>Uh
} `Q8D[
Z kS*CG
Kq?7#,_
public void setSFileName(String value) m88~+o<G%
{ 1)R)+`y
sFileName = value; z%KChU
} qb<gh D=j
s_[?(Ip{
S3<v?tqLr
public int getNSplitter() b#m47yTW9<
{ Gs6#aL}]R
return nSplitter; r%#qbsN
} ~4^e a
g3Q #B7A
yS43>UK_W+
public void setNSplitter(int nCount) Yru[{h8hw`
{ 4TKi)0 #7
nSplitter = nCount; }cT}G;L'-
} 3pp w_?k
} R3PhKdQ"
+{I\r|
Q.\>+4]1&&
/* QD<4(@c5|
**Utility.java ayD\b6Z2.
*/ [GuDMl3hC
package NetFox; \f LBw0
}B-A*TI<h
Dpd$&Wr0Y
public class Utility { UE4#j\
pUr[MnQLf
7" [;M
public Utility() ts]7 + 6V
{ .9xGLmg
Ae#6=]V+^
MH?B.2
} r Lh h
=<05PB
//线程睡眠 _:L*{=N
public static void sleep(int nSecond) K)?^b|D
{ ~c^-DAgB
try{ rYJ))@
Thread.sleep(nSecond); R}>Do=hAO
} B`F82_O
catch(Exception e) yjq )}y,tF
{ D:(f"
e.printStackTrace (); >DRs(~|V#
} vFOv IVp
} XbC8t &Q],
&J b.OCf
//日志 7N"Bbl
public static void log(String sMsg) .;2!c'mT9
{ IT(c'}
System.err.println(sMsg); M\&~Dmd
} UjaC( c
~^S-
aK{\8L3]
public static void log(int sMsg) mSfhl(<L
{ l.x }I"tf
System.err.println(sMsg); ECScx02
} !iVFzG @m
} )ta5y7np
6dL>Rzl$Dk
ry ?2 o!
/* @:&+wq_>A^
**TestMethod.java O[y`'z;C
*/ ?/(K7>`
package NetFox; b-?o?}*
Z?.*.<"Sj
;ZJ,l)BNO
public class TestMethod { X6,9D[Nw
^wa9zs2s;/
,NEs{! T
public TestMethod() 3kCbD=yF
{ ///xx/weblogic60b2_win.exe Y14R"*t~
try{ {1aAm+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #!jRY!2Vt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >!1f`
SiteFileFetch fileFetch = new SiteFileFetch(bean); s8[9YfuW
fileFetch.start(); 4C%>/*%8>
} ^-u HdafP
catch(Exception e){e.printStackTrace ();} w<Cmzkf
rcx;3Vne
S I7B6c
} P|4E1O
]$*{<
UD2<!a'T
public static void main(String[] args) +^?-}v
{ 2g6_qsqi
new TestMethod(); //lZmyP?
} Iv72;ZCh?6
} ]7kGHIJ|
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