http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); D.Q=]jOs
} M#VE]J
for(int i=0;i<nEndPos.length-1;i++) ^,8)iV0j_
{ J)~L
nEndPos = nStartPos[i+1]; bMMh|F
} U`d5vEhT
nEndPos[nEndPos.length-1] = nFileLength; 27"%"P.1
} n3Z5t
} 5b[jRj6
]0)|7TV*
O8u j`G 9
//启动子线程 f Tl<p&b
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D+z?wuXk
for(int i=0;i<nStartPos.length;i++) qA$*YIlK
{ cmg^J
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O#k6' LN?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S=nzw-(I
nStartPos,nEndPos,i); MIoEauf
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I`LuRlw
fileSplitterFetch.start(); $!(pF
} $lIz{ySJv
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lBTmx(_}}r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7:3$Ey
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !Kj,9NX{U
nEndPos = " + nFileLength); PGBQn#c<
// fileSplitterFetch[nPos.length-1].start(); ^Z#W_R\l
V<@ o<R
k"]dK,,
//等待子线程结束 _/!y)&4"
//int count = 0; ;z:UN}
//是否结束while循环 \":m!K;Z
boolean breakWhile = false; &8_gRP
<U >>ZSi
?)X,0P'
while(!bStop) )'%$V%9
{ [4C:r!
write_nPos(); [uls8 "^/j
Utility.sleep(500); u1PaHgi$
breakWhile = true; ,%Up0Rr,
&PK\|\\2
Q|L9gz[?
for(int i=0;i<nStartPos.length;i++) rJ{O(n]j
{ )ZqJh
if(!fileSplitterFetch.bDownOver) 9Z'8!$LYg
{ q51Uf_\/
breakWhile = false; p)3U7"q
break; {=QiZWu
} qt 2d\f
} 78OIUNm`
if(breakWhile) QC;^xG+W
break; W.0L:3<"
!\L/[:n
+g]yA3
//count++; ugx%_x6
//if(count>4) fUQ6Z,9
// siteStop(); S"$m]
} yH*6@P4:0=
Y=n4K<
,|plWIl~
System.err.println("文件下载结束！"); .?e\I`Kk^'
} ,NVsn
catch(Exception e){e.printStackTrace ();} k]HEhY
} g[7#w,o
Za8#$`zq
G\Ro}5TO
//获得文件长度 Bw64
public long getFileSize() *9c!^$V
{ ?Cg>h
int nFileLength = -1; pL%r,Y_^\x
try{ {=-\|(Bx
URL url = new URL(siteInfoBean.getSSiteURL()); tl'9IGlc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iVTGF<
httpConnection.setRequestProperty("User-Agent","NetFox"); @wC5 g 4E
/'DsB%7g
|{ PI102
int responseCode=httpConnection.getResponseCode(); -!L"')
if(responseCode>=400) X'% ;B
{ QZhjb
processErrorCode(responseCode); z,:a8LB#[
return -2; //-2 represent access is error njnDW~Snb
} -7&Gi +]
aKJQm'9Ks
R% ,<\d7
String sHeader; ZwerDkd
NDAw{[.%
BC;:
for(int i=1;;i++) ,b;{emX h
{ { e5/+W
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tP%{P"g3^
//Utility.log(in.readLine()); {$^DMANDx
sHeader=httpConnection.getHeaderFieldKey(i); *[R eb%
if(sHeader!=null) 0Ir<y
{ Z)xaJGbw
if(sHeader.equals("Content-Length")) dVo.Czyd
{ R &4Z*?S
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +@K09ge
break; ]a3iEA2 (
} lP!;3iJ B
} !\;FNu8_.
else ^3FE\V/=
break; ;/*6U
} P7f,OY<@%o
} f5==";eP
catch(IOException e){e.printStackTrace ();} ?k|H3;\
catch(Exception e){e.printStackTrace ();} JHJ~X v
hyT1xa
p/ >`[I
Utility.log(nFileLength); LJTQaItdqJ
d{de6 `
)&<=.q
return nFileLength; e=QK}gzX
} uH;-z_Wpn!
:BGA.
D\YE^8/
//保存下载信息（文件指针位置） @M8|(N%
private void write_nPos() 2JS`Wqy
{ Z0>DNmH*
try{ @hImk`&[N
output = new DataOutputStream(new FileOutputStream(tmpFile)); #vqo -y7@
output.writeInt(nStartPos.length); KyO8A2'U
for(int i=0;i<nStartPos.length;i++) $VQtwuYt
{ =FT98H2*|
// output.writeLong(nPos); z]bwnJfd
output.writeLong(fileSplitterFetch.nStartPos); "A)("
output.writeLong(fileSplitterFetch.nEndPos); xN@Pz)yo
} R1W}dRE}
output.close(); oejfU;+$
} M}wXJ8aF?
catch(IOException e){e.printStackTrace ();} Ep4Hqx $
catch(Exception e){e.printStackTrace ();} FHPXu59u
} !HJ$UG/\
AisN@
[J0v&{)?
//读取保存的下载信息（文件指针位置） =60~UM
private void read_nPos() q(5+xSg"gK
{ P0-Fc@&Y
try{ CCGV~e+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ACK1@eF
int nCount = input.readInt(); }V|{lvt.
nStartPos = new long[nCount]; ez9k4IO
nEndPos = new long[nCount]; rqlc2m,<-p
for(int i=0;i<nStartPos.length;i++) ^U8r0]9
{ Kw`VrcwjT
nStartPos = input.readLong(); eb8w~
nEndPos = input.readLong(); s$*'^:
} h`}3h< 8
input.close(); <_./SC
} $8BE[u|H2
catch(IOException e){e.printStackTrace ();} U`x bPQ
catch(Exception e){e.printStackTrace ();} Q\3 Z|%
} 1Fi86
qJ_1*!!91
Sm2>'C
private void processErrorCode(int nErrorCode) 8Z2.`(3c[
{ JkA|Qdj~Mr
System.err.println("Error Code : " + nErrorCode); $Vv}XMxw
} p=QYc)3F
<vbIp&
%AnW~v
//停止文件下载 l~Lb!;,dN
public void siteStop() 4E:bp
{ d'9:$!oz
bStop = true; 9><mp]E4
for(int i=0;i<nStartPos.length;i++) r CRgzC
fileSplitterFetch.splitterStop(); >uI$^y1D
gX?n4Csy'
9%iFV N'
} d=]U_+
} 0%;146.p
//负责部分文件的抓取 ^aRgMuU
**FileSplitterFetch.java s/1 #DM"
*/ KIVH!2q;
package NetFox; 8S;CFyT\n
]^\8U2q}
br,+45:
import java.io.*; 7e&\{*
import java.net.*; m$$?icA
/LQ:Sv7
$YG1z
public class FileSplitterFetch extends Thread { zG c[Z3N
(a6?s{(
m^{ xd2
String sURL; //File URL #rYENR[
long nStartPos; //File Snippet Start Position u; TvS |
long nEndPos; //File Snippet End Position WIh@y2&R
int nThreadID; //Thread's ID p11G#.0
boolean bDownOver = false; //Downing is over Jll-X\O`-
boolean bStop = false; //Stop identical O hR1Jaed
FileAccessI fileAccessI = null; //File Access interface rFL$QC2
396R$\q
.%0ne:5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Z]:BYX'
{ u&TdWZe
this.sURL = sURL; " B@jfa%
this.nStartPos = nStart; pyW u9
this.nEndPos = nEnd; =<<3Pkv7@
nThreadID = id; }1%r%TikY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |[cdri^?D
} cQFR]i
twk&-:'
fV ZW[9[
public void run() |Zq\GA
{ xNN@1P[*
while(nStartPos < nEndPos && !bStop) M>_= "atI
{ I/UQ'xx
+EASAq
8kW/DcLE
try{ %TK&)Q% h5
URL url = new URL(sURL); 4^!4eyQ^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w&lZ42(mF
httpConnection.setRequestProperty("User-Agent","NetFox"); s=EiH
String sProperty = "bytes="+nStartPos+"-"; ;>2#@QP
httpConnection.setRequestProperty("RANGE",sProperty); vg8O] YF
Utility.log(sProperty); ?G/hJ?3
Ds5NAp:x
T0FZ7
InputStream input = httpConnection.getInputStream(); )XVh&'(r
//logResponseHead(httpConnection); FUaNiAr[
IF?xnu
-WT3)On
byte[] b = new byte[1024]; {:Vf0Mhb
int nRead; TvrwVL)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Gidkt;lj
{ ~|) 9RUXr>
nStartPos += fileAccessI.write(b,0,nRead); 4S *,\q]q
//if(nThreadID == 1) !z=pP$81
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); & QY#3yj=
} 2X@G"
%N~;{!![p
"oE*9J?e
Utility.log("Thread " + nThreadID + " is over!"); K~>jApZ%
bDownOver = true; "r-l8r,
//nPos = fileAccessI.write (b,0,nRead); vO$ra5Z
} 7>x;B
catch(Exception e){e.printStackTrace ();} A'DVJ9%xB
} u3wL<$2[8
} X7e/:._SAH
sA_X<>vAKJ
kQ}s/*
//打印回应的头信息 +?e}<#vd'?
public void logResponseHead(HttpURLConnection con) zeTszT)
{ dB`b9)Tk0z
for(int i=1;;i++) YMAQ+A!
{ ^"tqdeCb=
String header=con.getHeaderFieldKey(i); I>((o`
if(header!=null) g[!Cj,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gNa#|
Utility.log(header+" : "+con.getHeaderField(header)); DM2Q1Dh3
else D_aR\
break; !Y%D 9
} 9N}W(>
} h3h8lt_|
P{lh)m>
j<$R4A1
public void splitterStop() f8!l7{2%q
{ sfC@*Y2XT
bStop = true; lCE2SKj
} h>tsis'N9
[s %\.y(q
y#r\b6
} 6{^*JC5nj
cMtJy"kK
eG^z*`**
/* /'Bdq?!B&
**FileAccess.java /\~W$.c
*//文件访问(定位，写) M,L@k
package NetFox; 3*\8p6G
import java.io.*; t~~r-V":
kGj]i@(PA4
mCrU//G
public class FileAccessI implements Serializable{ {Pvr??"r
Isp_U5M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #wD7 \X-f
RandomAccessFile oSavedFile; di<B~:l58
long nPos; sWW\bK0B4
y7; 5xF?q
Heohe|an
public FileAccessI() throws IOException t;XS;b%
{ XbXgU#%
this("",0); *cy.*@d
} .9I_NG
r1hD %a
ZE ^u.>5
public FileAccessI(String sName,long nPos) throws IOException dAwS<5!
{ wL'C1Vr
oSavedFile = new RandomAccessFile(sName,"rw"); < [w++F~
this.nPos = nPos; !pV<n
oSavedFile.seek(nPos); 1G_xP^H!
} a}GAB@YI
Vd[2u
KPg[-d
public synchronized int write(byte[] b,int nStart,int nLen) \ >(zunL
{ FP@A;/c
int n = -1; UR\ZN@O
try{ Wb'*lT0=
oSavedFile.write(b,nStart,nLen); 1YFAr}M
n = nLen; x/[8Wi,yB
} K5+!(5V~
catch(IOException e) %)dI2 J^Xf
{ :3 PGf
e.printStackTrace (); -|$*l Q
} e Ri!\Fx
_jk|}IB;X
]t7ClT)n!
return n; w=gQ3j#s
} U!_sh<
6e&g$R v
TVj1C
} dgm+U%E
&F86SrsI
*+&z|Pwv[^
/* hxP6C6S
**SiteInfoBean.java w4`!Te
*/ `GP3D~
package NetFox; Ckw83X
S{Rh'x\B
H.)fOctbO
public class SiteInfoBean { IS .g);Gj
t0+t9w/fTP
2kC^7ZAwu
private String sSiteURL; //Site's URL [gTQ-
private String sFilePath; //Saved File's Path }3Df]
private String sFileName; //Saved File's Name jf2y0W>6s
private int nSplitter; //Count of Splited Downloading File 8R BDJ
enWF7`
yi&?d&rK
public SiteInfoBean() !OV|I
{//nSplitter的缺省值为5 57'q;I
//default value of nSplitter is 5 :Q8g?TZ
this("","","",5); x ru(Le}E
} F: f2s:<
?UU5hek+m
{kT#o3,>w6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pFS F[9?e>
{ K@y-)I2]
sSiteURL= sURL; 9F/|`
sFilePath = sPath; 1g+LF[*-~
sFileName = sName; (tgEa{rPAP
this.nSplitter = nSpiltter; WvIK=fdZ$
x0y%\
cvn-*Sj
} =H L9Z
U[blq M
@F>[DW]O
public String getSSiteURL() nm<L&11
{ p, !1 3X
return sSiteURL; (Be$$W
} R %Rv
N=hSqw[
3`mC"ab /
public void setSSiteURL(String value) ::kpl2r\c
{ B'NS&7+].
sSiteURL = value; 9)1P+c--
} M|$H+e }:
Y}85J:q]
W^-hMT]uD
public String getSFilePath() hQ\#Fhu7
{ -Mit$mFn
return sFilePath; r[Zg 2
} {\ A_%
Iwnj'R7:
`#-p,NElV
public void setSFilePath(String value) -Pv P
{ ,^UcRZ8.H
sFilePath = value; bEBZ!ghU
} h[vAU 9f)
/<(R
k9.u[y.
public String getSFileName() 6nM rO$i0k
{ *g}vT8w'}
return sFileName; d@_'P`%-
} h#$_<U
M80}3mgP~
_Y}^%eFw
public void setSFileName(String value) ?z*W8b]'
{ yYVW"m
sFileName = value; }])GQ@
} O~7p^i}
>$d d9|[
J@=!w[v+
public int getNSplitter() $`cy'ZaF
{ @B}&62T
return nSplitter; Yb,G^+;
} S(q4OQB{
e7)>U!9c9
z:@d@\$?
public void setNSplitter(int nCount) +]aD^N9['
{ w*]_FqE
nSplitter = nCount; @]}Qh;a~
} 3hp tP
} 7lnM|nD
o.v,n1Nm
Q*TQ*J7".X
/* ]~4}(\u
**Utility.java 0TuNA\Ug+
*/ 3|z;K,`Fw
package NetFox; XFLjVrX[
:Kt{t46)
*J*zml3
public class Utility { ;h*"E(Pp
)o}=z\M-bN
uC <|T
public Utility() gu~-}
{ /i7>&ND.r
EX[l0]fj
v=8~ZDY
} x_>"Rnv:K
see'!CjVo2
//线程睡眠 "N=&4<]I5
public static void sleep(int nSecond) :6HiP&<
{ z^SN#v$
try{ 'Gm!Jblo@
Thread.sleep(nSecond); K~9 jin
} am)J'i,
catch(Exception e) j$JV(fz
{ G5X|JTzpu<
e.printStackTrace (); g/J^K*3]
} <3J=;.\6
} |iF1A
7ZR0M&pX
//日志 rK0|9^i{
public static void log(String sMsg) J}93u(T5
{ ~h~r]tV*+
System.err.println(sMsg); ZFd{q)qe
} E(L^hZMc
$$)<(MP3
.WPuQZ!
public static void log(int sMsg) )Uoe~\
{ /Wta$!X{-
System.err.println(sMsg); pB{ f-M:D
} b_"V%<I
} )GF
07E".T%Ts
_3-,3ia
/* ~"hAb2
**TestMethod.java 'ra_Zg[j
*/ OHXeqjhy
package NetFox; `04Y ;@w
$4fjSSB~
$;g%S0:3)
public class TestMethod { q0xE&[C[M
Luu-c<*M
wMR[*I/
public TestMethod() 55)ep
{ ///xx/weblogic60b2_win.exe xDAA`G
try{ {U2|):
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N'q/7jOy
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u6CMRZ$
SiteFileFetch fileFetch = new SiteFileFetch(bean); 22H=!.DJ
fileFetch.start(); S7\jR%pb
} M4$4D?
catch(Exception e){e.printStackTrace ();} Kk"B501
iJ~iJ'vf
|cBF-KNZ
} w{UKoU
_{@}Fd?o
1OJD\wc
public static void main(String[] args) okW)s*7
{ 6CzvRvA*P
new TestMethod(); ,J4a~fPf
} vU=k8
} 7dL=E"WL
点击下载更多相关资料