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)); /,X[k !
} E[*Fz1>
for(int i=0;i<nEndPos.length-1;i++) ]6{*^4kX
{ W3;#fa:[L
nEndPos = nStartPos[i+1]; @EDs~ lPv
} Nof3F/2 N&
nEndPos[nEndPos.length-1] = nFileLength; KGWyJ
} 9(L)&S{4K
} `8I&7c
g=]u^&
Oer^Rk
//启动子线程 .>mr%#p
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sp ]zbX?
for(int i=0;i<nStartPos.length;i++) .{=$!8|&I9
{ [<{Kw=X__2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e+j)~RBnu3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \N4 y<
nStartPos,nEndPos,i); i-'9AYyw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :OkT? (i
fileSplitterFetch.start(); q-`RI*1]
} n':!,a[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q\WC+,_%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Cxcr/9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r} P<iX
nEndPos = " + nFileLength); c1_5, 1U'
// fileSplitterFetch[nPos.length-1].start(); S_T1y
]a!xUg!S
1|?05<8
//等待子线程结束 ! /NG.Wf
//int count = 0; J%jB?2 1:o
//是否结束while循环 ~j#]tElb
boolean breakWhile = false; :T._ba3|
v\,N5
%rF?dvb;?
while(!bStop) {XWZ<OjG
{ k~/>b~.c
write_nPos(); =r.mlc``W
Utility.sleep(500); }->.k/vc
breakWhile = true; <N`J`J-[
#_|sgS?1
K3' niGT
for(int i=0;i<nStartPos.length;i++) rC7``#5
{ 2<][%> '
if(!fileSplitterFetch.bDownOver) 9Li%KOY
{ `iJhG^w9M
breakWhile = false; fsEzpUY:{W
break; =;3fq-
} HoLv`JA
} :KKa4=5L
if(breakWhile) 3 AHY|
break; +R\vgE68
sT/c_^y
RC^9HuR&
//count++; 5|I[>Su
//if(count>4) UDe |Sb
// siteStop(); Bcjx>#3?L
} /c$\X<b);
r&2~~_d3y
{w8 NN-n
System.err.println("文件下载结束！"); U^.4Hy&D
} LT~YFS
catch(Exception e){e.printStackTrace ();} Y'u7 IX}
} Hh4 n
=L5GhA~
`g_"GE
//获得文件长度 p)=~% 7DV
public long getFileSize() YqV8D&I
{ 37q@rDm2
int nFileLength = -1; ~+H" -+
try{ Cv*x2KF G
URL url = new URL(siteInfoBean.getSSiteURL()); 2iU7 0(H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VN'Wq7>6
httpConnection.setRequestProperty("User-Agent","NetFox"); ~fa(=.h
N6T{
M^7MU}5w
int responseCode=httpConnection.getResponseCode(); rFZrYm
if(responseCode>=400) ooj~&fu
{ ?+t1ME|
processErrorCode(responseCode); 8LI-gp\ 2
return -2; //-2 represent access is error {Rear2
} `Rdm-[&
CAU0)=M
oR~e#<$;
String sHeader; 97,rE$bC
YxGcFjJ
Otz E:qe
for(int i=1;;i++) KT.?Xp:z
{ ]=EM@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;@nFVy>U
//Utility.log(in.readLine()); tj*y)28-
sHeader=httpConnection.getHeaderFieldKey(i); /?6gdN
if(sHeader!=null) M0' a9.d
{ E_1="&p
if(sHeader.equals("Content-Length")) m3^/:<
{ {3Y )rY!z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]}mxY vu_i
break; R|P_GN6>
} 4<X!<]3]
} &6j<ca
else erl:9.
break; 5 #]4YI;
} >|o_wO
} e/8z+H^H
catch(IOException e){e.printStackTrace ();} /U$8TT8+-
catch(Exception e){e.printStackTrace ();} 45@]:2j
O3N_\B:
C*X G_b ]
Utility.log(nFileLength); Q2p)7G
hKlZi!4J
(9gOtJ
return nFileLength; oA tsUF+a
} [Qdq}FYr
ir:d'g1k
#Y93y\
//保存下载信息（文件指针位置） dp5f7>]:(
private void write_nPos() %@R~DBS
{ XMRNuEU
try{ *8ExRQZ$
output = new DataOutputStream(new FileOutputStream(tmpFile)); `*\{.;,]#
output.writeInt(nStartPos.length); .9|uQEL
for(int i=0;i<nStartPos.length;i++) ue8qIZH
{ l12$l<x&M
// output.writeLong(nPos); (X6sSO
output.writeLong(fileSplitterFetch.nStartPos); O!Wd5Y
output.writeLong(fileSplitterFetch.nEndPos); .1QgK
} tJ=di5&
output.close(); . -"E^f
} (shK
catch(IOException e){e.printStackTrace ();} ~"!a9GZ
catch(Exception e){e.printStackTrace ();} @-#T5?
} 3P <'F2o
[B0K
[rreFSy#@
//读取保存的下载信息（文件指针位置） h7;bclU
private void read_nPos() ^*^/]vM
{ uO >x:*^8
try{ a}d6o;li
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fMeZ]rb
int nCount = input.readInt(); PK&2h,Cu+
nStartPos = new long[nCount]; 0m+8P$)C%
nEndPos = new long[nCount]; fj4^VXD
for(int i=0;i<nStartPos.length;i++) n~Szf
{ }~o ikN:
nStartPos = input.readLong(); z8Q"%@
nEndPos = input.readLong(); =f:(r'm?r.
} ACV ek
input.close(); DI&MC9j(
} YCw('i(|
catch(IOException e){e.printStackTrace ();} D22Lu;E
catch(Exception e){e.printStackTrace ();} q2_`v5t
} _a+ICqR
ex?\c"
"L3Xd][
private void processErrorCode(int nErrorCode) TRKgBK$,
{ d<@Mdo<;?g
System.err.println("Error Code : " + nErrorCode); T+RZ
} vN{-?
`ycU-m==
~2/{3m{3A
//停止文件下载 ~F#A Pt
public void siteStop() i~&c|
{ \~X&o% y
bStop = true; "A]Y~iQ
for(int i=0;i<nStartPos.length;i++) zfjTQMaxh
fileSplitterFetch.splitterStop(); (:Cc3
oA~4p(
(3md:r<-
} P 4;{jG
} A1*4*
//负责部分文件的抓取 agaq`^[(P
**FileSplitterFetch.java l_v*7d
*/ 1.SkIu%
package NetFox; wk02[
V2yveNz\7
[[qwaI
import java.io.*; eO{@@?/y
import java.net.*; 67J*&5? |
W3LP ~
D{AFL.r{
public class FileSplitterFetch extends Thread { F@hYA
z/1hqxHl
B4O6>'
String sURL; //File URL "E>t, D
long nStartPos; //File Snippet Start Position ):bu;3E
long nEndPos; //File Snippet End Position ,deUsc
int nThreadID; //Thread's ID FD6v/Y
boolean bDownOver = false; //Downing is over `Lz1{#F2G
boolean bStop = false; //Stop identical n9fk,3
FileAccessI fileAccessI = null; //File Access interface "g `nsk
g8yN%)[
_=6OP8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^'B-sz{{
{ u3Do~RyL[
this.sURL = sURL; F^'v{@C
this.nStartPos = nStart; ?Bu}.0ku-$
this.nEndPos = nEnd; F14(;'Az
nThreadID = id; )!C7bTv 4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <*YO~S(R
} ;,0lUcV
\n@V-b
9Q@*0-
public void run() oP]L5S&A
{ ogeRYq,g
while(nStartPos < nEndPos && !bStop) (/fT]6(
{ )C}KR`"
lcig7%
5OB]x?4]
try{ RqGVp?
URL url = new URL(sURL); b5Q8pWZg,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +Pw,Nl\KD
httpConnection.setRequestProperty("User-Agent","NetFox"); GEtbs+[
String sProperty = "bytes="+nStartPos+"-"; pAg$oe#
httpConnection.setRequestProperty("RANGE",sProperty); d~<QAh#rG
Utility.log(sProperty); wsfysat$
/Ri,>}n
] SK[C" S
InputStream input = httpConnection.getInputStream(); 6F`\YSn+
//logResponseHead(httpConnection); n4>cERfa
h]P/KVqR.
S'?fJ.
byte[] b = new byte[1024]; NQ!<f\m4n
int nRead; J"bD\%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E{gv,cUM
{ ou;qO 5CT
nStartPos += fileAccessI.write(b,0,nRead); hrT%XJl
//if(nThreadID == 1) QSmJ`Bm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]-KV0H
} @,YlmX}
K_##-6>
H56 ^n<tg
Utility.log("Thread " + nThreadID + " is over!"); %uEtQh[
bDownOver = true; .\)k+ R
//nPos = fileAccessI.write (b,0,nRead); qsvpW%?aE
} 4OEKx|:5n
catch(Exception e){e.printStackTrace ();} =43d%N
} A|C_np^z2
} M*H< n*
%|jzEBz@
/=trj5h
//打印回应的头信息 1uC;$Aj6:
public void logResponseHead(HttpURLConnection con) 1$OVe4H1
{ jIZ+d;1
for(int i=1;;i++) bx7\QU+
{ K>LpN')d
String header=con.getHeaderFieldKey(i); 9ET/I$n
if(header!=null) G)~MbesJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :;_#5
Utility.log(header+" : "+con.getHeaderField(header)); ;ct)H* y
else QmHwn)Ly
break; 7&px+155
} Q!x`M4
} /B=l,:TnJ
(h|ch#
=Pj@g/25u
public void splitterStop() lJ'trYaq7
{ Ym:{Mm=ud
bStop = true; s<d!+<
} KJ pj
Y.9~Bo<<r
PnJ*Zea
} mb~./.5F
;'hi9L
Lb^(E-
/* W'V@
**FileAccess.java >"bnpYSe
*//文件访问(定位，写) -+' #*V
package NetFox; a!?.F_T9A
import java.io.*; K@*rVor{
+Tp%5+E
0&Qsk!-B
public class FileAccessI implements Serializable{ UE{,.s
$kIo4$.Y$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &8waih(|
RandomAccessFile oSavedFile; $mD>rx
long nPos; ret0z|
bz$Qk;m=H
H):-!?:
public FileAccessI() throws IOException 1N>6rN
{ `LE^:a:8,
this("",0); s{cKBau
} 2@4x"F]U;
m]1!-`(*
N-D(y
public FileAccessI(String sName,long nPos) throws IOException Yg$@Wb6
{ {:3.27jQ
oSavedFile = new RandomAccessFile(sName,"rw"); l3BD <PB2S
this.nPos = nPos; 2DUr7rM
oSavedFile.seek(nPos); [h^f%
} C#ZhsWS!b
6{ C Fe|XN
[pr 9 $Jr
public synchronized int write(byte[] b,int nStart,int nLen) {vLTeIxf.G
{ tnN'V
int n = -1; Tt`L(oF
try{ ,7t3>9-M"
oSavedFile.write(b,nStart,nLen); ;FcExg|k
n = nLen; U%h7h`=F?
} 70duk:Ri0
catch(IOException e) qPqy4V.;
{ Uld_X\;Q4
e.printStackTrace (); 9e-*JYF]C
} u>81dO]H
xJN|w\&
'N*!>mZ<
return n; 0Y[*lM-
} ~Vwk:+):
m;1'u;
0GS{F8f~,
} y-%nJD$
Xm%iPrl D
2ve lH;
/* ss/h[4h4h
**SiteInfoBean.java DgC3> yL
*/ 3Ca \`m)l
package NetFox; n}=rj7
vlAO z
4}+xeGA$
public class SiteInfoBean { zjea4>!A2
E!dz/.
lj4%(rB=
private String sSiteURL; //Site's URL bd,Uz%o_
private String sFilePath; //Saved File's Path ]bs+:
private String sFileName; //Saved File's Name ht2 f-EKf{
private int nSplitter; //Count of Splited Downloading File Xg,0/P~
7WgIhQ~
n?zbUA#
public SiteInfoBean() $Z,i|K;
{//nSplitter的缺省值为5 3fm;r5
//default value of nSplitter is 5 '`9%'f)
this("","","",5); aB=vu=hF
} U)u\1AV5
a#YuKh?
$K+4C0wX`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Sjw2 j#Q
{ 1RCXc>}/
sSiteURL= sURL; lr-12-D%-
sFilePath = sPath; 2T//%ys=
sFileName = sName; L[CU
this.nSplitter = nSpiltter; @>M8Pe
&/sGh0
oK#\HD4U
} K5 5} Wi
DLNa6
olYPlHF
public String getSSiteURL() ;RNM
{ caGML|DeI
return sSiteURL; c:3@[nF~
} o G(0i
w9G_>+?E
f0/jwfL
public void setSSiteURL(String value) l.XknF
{ Fl B, (Cm
sSiteURL = value; ;3 G~["DA
} $?[1#%
p.@0=)
uo]Hi^r.l
public String getSFilePath() S9$o
{ jN31\)/i
return sFilePath; #S@UTJa
} )`B -O::
-Pqi1pj]
Tg3:VD
public void setSFilePath(String value) <I>%m,
{ =@Q#dDnFu%
sFilePath = value; ,AdusM
} ]jHgo](%
>W>##vK
X*TuQ\T
public String getSFileName() L{cK^ ,
{ DkDw>Nx<rs
return sFileName; 70'}f
} Bv2z4D4f+
x?%rx}h
rFKo E%
public void setSFileName(String value) AeNyZ[40T
{ v(qV\:s}m
sFileName = value; `V]egdO
} jf$JaY
bHhC56[M
,"P5D&,_
public int getNSplitter() lAdOC5+JX
{ 4(` 2#
return nSplitter; w^ixMn~nLF
} k)N2+/
<bEN8b
:'5G_4y)h
public void setNSplitter(int nCount) =giM@MV
{ /Oq1q._9F
nSplitter = nCount; hg[l{)Q
} *4(/t$)pEl
} XX]5T`D
DePV,.
MILIu;[{#r
/* y+K7WUwhq
**Utility.java AzHIp^
*/ P`\m9"7
package NetFox; S/@dkHI'
- XE79 fQ
/2g)Z!&+L
public class Utility { %k/ k]:s
iYO wB'z
5en [)3E
public Utility() L eG7x7n
{ r[.zLXgK
N oX_?
m&Y;/kr
} 8CHb~m@^$
.nj?;).
//线程睡眠 Rz<d%C;R
public static void sleep(int nSecond) /E`l:&89)
{ l%sp[uqcg
try{ {ED(O-W
Thread.sleep(nSecond); 5]4<!m
} AJ;u&&c4C\
catch(Exception e) ka?IX9t\
{ L Q I: ]d
e.printStackTrace (); ) xfc-Q
} TEaD-mY3
} -4*'WzWr
s=^r/Sz902
//日志 u^#4G7<
public static void log(String sMsg) 33#7U+~]@
{ *_4n2<W$
System.err.println(sMsg); `nd#< w>
} 3bg4#c
^DW#
/(hP7_]`2
public static void log(int sMsg) bqg]DO$*
{ /%J&/2Wz
System.err.println(sMsg); < "L){$
} ?)Czl4J
} IyG= 7
"oE^R?m
D,}'E0
/* $nGbT4sc
**TestMethod.java Z,|1G6f@
*/ f_re"d 3u
package NetFox; 5{R#h :
dI#8CO
D&z'tf5
public class TestMethod { jm#d7@~4
_SBp66 r
H0D>A<Ue
public TestMethod() 9Sx<tj_4P{
{ ///xx/weblogic60b2_win.exe WTV3p,;6a
try{ c-s`>m
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ADLa.{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qrkRD*a
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9I`Mm}v@
fileFetch.start(); Wvut)T
} 6mI_Q2
catch(Exception e){e.printStackTrace ();} w+).pcG(*
NgE&KPj\
F(KH-
} !_XU^A>
\pewbu5^
#FQm/Q<0
public static void main(String[] args) )5GdvqA
{ hSx+{4PZ
new TestMethod(); $+lz<~R
} 6yu*a_
} )F%wwc^r
点击下载更多相关资料