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)); /@qnEP%
} io^L[
for(int i=0;i<nEndPos.length-1;i++) G}8Zkz@+
{ DJ.n8hne
nEndPos = nStartPos[i+1]; m&!4*D
} v"3($?au0
nEndPos[nEndPos.length-1] = nFileLength; \Jy/ a-
} Lw_s'QNWR
} YOE!+MiO
Z36C7 kw
M`u&-6
//启动子线程 Fx6]x$3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6! .nj3$*
for(int i=0;i<nStartPos.length;i++) :+*q,lX8
{ P|'eM%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {$H-7-O$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), JDp{d c
nStartPos,nEndPos,i); ^]{m*bEkR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {2,vxGi
fileSplitterFetch.start(); 9?J 3G,&
} _`-trE.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ckhU@C|=*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E8LA+dKN:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F(}~~EtPHo
nEndPos = " + nFileLength); CaE1h9
// fileSplitterFetch[nPos.length-1].start(); RJhafUJ zH
OPe3p {]
h}$g}f%$+
//等待子线程结束 :)=>,XwL8
//int count = 0; R;l;;dC=
//是否结束while循环 l>){cI/D#
boolean breakWhile = false; '^10sf`"
YDxEWK<
1r?hRJ:'
while(!bStop) p()#+Xy
{ lC8Z@wkjO
write_nPos(); 2>+(OL4l
Utility.sleep(500); `G0GWh)`x
breakWhile = true; dgp1B\
=9yh<'583
T j(MIFi|5
for(int i=0;i<nStartPos.length;i++) Z`]r)z%f
{ ,$A'Y
if(!fileSplitterFetch.bDownOver) {a9( Qi
{ ' Ih f|;r
breakWhile = false; ='G-wX&k
break; JG/Pc1aK
} "&Rt&S
} pB5#Ho>S
if(breakWhile) rHaj~s 4
break; )sZJH9[K
?DrA@;IB
=8V 9E
//count++; YMr2|VEU[
//if(count>4) |w].*c}Z
// siteStop(); A~)#
} h"3Mj*s
N(Sc!rX
u8Ak2:
System.err.println("文件下载结束！"); \`U=pZJ
} s~'"&0Gz
catch(Exception e){e.printStackTrace ();} (J 1:J
} GTuxMg`
fHd|tl
vN9R.R
//获得文件长度 %5$)w;p.$'
public long getFileSize() mJNw<T4!/
{ 38E %]*5F
int nFileLength = -1; ;_p$5GVR|
try{ L.?QZN%cN
URL url = new URL(siteInfoBean.getSSiteURL()); s C>Oyh:%!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yQ!I`T>a
httpConnection.setRequestProperty("User-Agent","NetFox"); q5xF~SQGw2
LE}V{%)xD
h<<uef9
int responseCode=httpConnection.getResponseCode(); U[EZ,7n8
if(responseCode>=400) ^V7'S<
{ YN}vAFR`
processErrorCode(responseCode); |}><)}
return -2; //-2 represent access is error VjLv{f<p
} /Os6i&;
!9t,#?!
WCD)yTg:ES
String sHeader; dt||nF
ZA+w7S3
.]w=+~h
for(int i=1;;i++) [9^lAhX
{ ("KtJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lG5KZ[/Or
//Utility.log(in.readLine()); '\M]$`Et
sHeader=httpConnection.getHeaderFieldKey(i); 8+@j %l j
if(sHeader!=null) =6'Fm$R
{ ]{| wU.
if(sHeader.equals("Content-Length")) |/;;uK,y
{ Marx=cNj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); < Dt/JA(p
break; U#Wg"W{
} *3\*GatJ
} H~ E<ek'~
else %<0'xJ%%Q
break; [\3W_jR
} q ;"/i*+3
} 7epil
catch(IOException e){e.printStackTrace ();} t0_4jVt
catch(Exception e){e.printStackTrace ();} 3<)+)n
Z 4QL&?U
R-YNg
Utility.log(nFileLength); R} X"di
k8c(|/7d
jwpahy;\WL
return nFileLength; |Iknk,
} kvG.?^ v
Lpohc4d[V
*,|x p
//保存下载信息（文件指针位置） zY9CoadZ
private void write_nPos() 3i1TBhs6
{ Ae\:{[c_D
try{ iNr&;
output = new DataOutputStream(new FileOutputStream(tmpFile)); H'+3<t>
output.writeInt(nStartPos.length); !dq$qUl/
for(int i=0;i<nStartPos.length;i++) *ze,X~8-
{ V|G*9^Y
// output.writeLong(nPos); UD=[::##
output.writeLong(fileSplitterFetch.nStartPos); qP0UcG
output.writeLong(fileSplitterFetch.nEndPos); 22'Ra[
} C8W_f( i~
output.close(); xXlx}C
} `S+n,,l
catch(IOException e){e.printStackTrace ();} xX|f{)<
catch(Exception e){e.printStackTrace ();} RzU9]e
} EM(%|#
@/,0()*dL
{n&GZG"f
//读取保存的下载信息（文件指针位置） #jJ0Mxg
private void read_nPos() W_6gV
{ *j(UAVp
try{ pk`5RDBu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v"o_V|
int nCount = input.readInt(); ]ddH>y&o
nStartPos = new long[nCount]; WcQkeh3n
nEndPos = new long[nCount]; 0{ _6le]
for(int i=0;i<nStartPos.length;i++) pedyWA>
{ 4 |bu= T
nStartPos = input.readLong(); %}JSR y
nEndPos = input.readLong(); \u04m}h]
} u{7->[=
input.close(); bI^F(
} L1WvX6
catch(IOException e){e.printStackTrace ();} ?9%$g?3Z
catch(Exception e){e.printStackTrace ();} X"vDFE`?
} v,Zoy|Lu
4]FS jVO
.K1wp G[4
private void processErrorCode(int nErrorCode) ]TJ258P}
{ Nv|0Z'M
System.err.println("Error Code : " + nErrorCode); nBLb1T
} re,}}'
aK_k'4YTm
I2krxLPd
//停止文件下载 \%B7M]P
public void siteStop() c[T@lz(!
{ VoQhzp6&
bStop = true; mN>(n+ly
for(int i=0;i<nStartPos.length;i++) kGL3*x
fileSplitterFetch.splitterStop(); z`eMb
w+Gav4
R\Ckk;<$
} _T7XCXEk
} 6y "]2UgQk
//负责部分文件的抓取 e+<|
**FileSplitterFetch.java p>f?Rw_
*/ |j{]6Nu
package NetFox; ?*[35XUd
oad /xbp@/
yu@Pd3
import java.io.*; 8F'm#0
import java.net.*; d(:I~m
Bj"fUI!dK
jP0TyhM
public class FileSplitterFetch extends Thread { u.*}'C>^^v
Ck>]+rl
;.rY`<|
String sURL; //File URL g3yZi7b5FU
long nStartPos; //File Snippet Start Position $pt~?ZZ3-
long nEndPos; //File Snippet End Position :Rnwyj])
int nThreadID; //Thread's ID Kr<UPr
boolean bDownOver = false; //Downing is over K`60[bdp
boolean bStop = false; //Stop identical 0P!Fci/t
FileAccessI fileAccessI = null; //File Access interface /1D.Ud^
UR S=1+
=;F7h @:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ra6}<o
{ LU8:]zOY
this.sURL = sURL; |/$954Hr#<
this.nStartPos = nStart; /d/]#T[Z9
this.nEndPos = nEnd; ~=t9-AF-
nThreadID = id; 'NCx<0*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sTep2W.9
} 'H4?V
+EqL|
gjFQDrz(
public void run() R3LIN-g(
{ rhX?\_7o
while(nStartPos < nEndPos && !bStop) )O$S3ojZ
{ ,7DyTeMpN
JiuA"ks)
_^ic@h3'X~
try{ k7L4~W
URL url = new URL(sURL); =Zsxl]h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2- (}=N
httpConnection.setRequestProperty("User-Agent","NetFox"); z]LVq k
String sProperty = "bytes="+nStartPos+"-"; k,; (`L
httpConnection.setRequestProperty("RANGE",sProperty); jxt]Z3a~0
Utility.log(sProperty); $!_}d
~*+evAP
V$oj6i{ky
InputStream input = httpConnection.getInputStream(); i70\`6*;B
//logResponseHead(httpConnection); ?YDMl
}W[=O:p
KoWG:~>|
byte[] b = new byte[1024]; 2R^Eea
int nRead; .3@Pz]\M#>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rY1jC\
{ ='C;^ Bk
nStartPos += fileAccessI.write(b,0,nRead); 3H4T*&9;n
//if(nThreadID == 1) E9t8SclV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZP&iy$<L
} qSD3]Dv"
\5=4!Ez
5Z"N2D)."
Utility.log("Thread " + nThreadID + " is over!"); hstGe>f[6
bDownOver = true; Tu,nX'q]m
//nPos = fileAccessI.write (b,0,nRead); LfK/wSvWw
} \_i22/Et
catch(Exception e){e.printStackTrace ();} d>c`hQ(V
} mv`b3 $
} 78<fbN5}r
a5d_= :S;
i.eMrzJ|
//打印回应的头信息 oR7f3';?6
public void logResponseHead(HttpURLConnection con) oYJ<.Yxeb
{ f8UO`*O
for(int i=1;;i++) Ad>@8^
{ N+H[Y4c?F&
String header=con.getHeaderFieldKey(i); QA)"3g
if(header!=null) ed3wj3@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); D5].^*AbZ
Utility.log(header+" : "+con.getHeaderField(header)); /+. m.TF
else 1|>bG#|
break; :!fY;c?
} g?Rq .py]!
} |<y1<O>F
HW'I$ .
6@FxPi9|#
public void splitterStop() w_LkS/
{ 6{g&9~V
bStop = true; |RqCI9N6
} l <Z7bo
,W/Y@ScC
RQ#9[6w!v
} 3hzz*9/n
yZNg[KH
="Azg8W
/* o>m*e7l,
**FileAccess.java Pi,86?
*//文件访问(定位，写) f'qM?GlET
package NetFox; x8wsx F
import java.io.*; uBC#4cX`D*
2uF'\y
9'|_1Q.b^
public class FileAccessI implements Serializable{ 4Yt'I#*
jxYze/I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /R6\_oM
RandomAccessFile oSavedFile; Vyc
long nPos; PfhKomt"
,Hp7`I>/
d4A:XNKB
public FileAccessI() throws IOException {7 ](-
{ ?f!&M
this("",0); SK*<H~2
} 3J3wKw!`
>rYMOC~
t+,2 p|B
public FileAccessI(String sName,long nPos) throws IOException y"K[#&,0
{ 9tmnx')_
oSavedFile = new RandomAccessFile(sName,"rw"); )U8=-_m
this.nPos = nPos; q!Z{qt*`um
oSavedFile.seek(nPos); IL?"g{w
} y7'9KQ
S]4!uv^y
7$*x&We
public synchronized int write(byte[] b,int nStart,int nLen) 4]xD-sc
{ X8~?uroq
int n = -1; NZ+TTMv
try{ uw@-.N^
oSavedFile.write(b,nStart,nLen); bY~V?yNgKM
n = nLen; ^^YP kh6sS
} w.+G+r=
catch(IOException e) {rygIl{V
{ V%`\x\Xat
e.printStackTrace (); o}52Qio
} n9Vr*RKM)
r=]$>&
ws$kwSHq
return n; Dh<}j3]
} C[><m2T
jm'^>p,9G
hdH3Jb_hl(
} <EY{goW
Q0g^%
g?@fHFct
/* R\x3'([A5
**SiteInfoBean.java f$--y|=
*/ $Xs`'>,"
package NetFox; B!4~A{
z0&Y_Up+5
0Ld"df*
public class SiteInfoBean { \86NV="U
f7;<jj;w7
~CHVU3
private String sSiteURL; //Site's URL {??bJRT
private String sFilePath; //Saved File's Path HzsQ`M4cA
private String sFileName; //Saved File's Name ,hp8b$
private int nSplitter; //Count of Splited Downloading File h:KEhj\d?
N%)q.'M
Sf2xI'
public SiteInfoBean() '*<I<? z;
{//nSplitter的缺省值为5 /*t H$\6*
//default value of nSplitter is 5 Y<_;8%S
this("","","",5); {W=5 J7
} !&5*H06
~"8r=8|
yl0;Jx?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q07&7SH_
{ yI/ FD
sSiteURL= sURL; %8xKBL]J
sFilePath = sPath; 3u< ntx ><
sFileName = sName; ZVrZkd`
this.nSplitter = nSpiltter; ClNuO
lAkg47i
E;An':j
} o/& IT(v
` }B,w-,io
5kojh _\
public String getSSiteURL() 5<P6PHdY
{ AHHV\r
return sSiteURL; 2rb@Md]dx
} as@? Kv
yD@1H(yM
~ ea K]|
public void setSSiteURL(String value) d\25
{ AJ)&+H
sSiteURL = value; D ,[yx='
} 45OAJ?N
bD-OEB
p1W6s0L
public String getSFilePath() #WS>Z3AY
{ gEw9<Y
return sFilePath; L~RFI&b
} ,H1K sN
>]uu?!PU
E()%IC/R
public void setSFilePath(String value) ^x_$%8
{ ae](=OQ
sFilePath = value; C~C`K%7
} lQy-&d|=#^
) $0>L5d:
+r&:c[
public String getSFileName() WdB\n/BWB
{ JoZSp"R
return sFileName; JpxQS~VX
} 12;YxW>[
~Yc!~Rz
@4]{ZUV
public void setSFileName(String value) [B+:)i
{ {'z$5<|
sFileName = value; 9ExI,
} s+z5"3'n
`6;$Z)=.
L\t_zf_0
public int getNSplitter() a6O <t;&
{ cBv"d ~
return nSplitter; '+3C2!
} /)kx`G_
IAmZ_2
vVrM[0*c
public void setNSplitter(int nCount) <0qhc$M
{ |~PaCw8-ge
nSplitter = nCount; j; R20xf0
} gXM+N(M-
} cOZBl;}
p1K]m>Y{?
M{)&SNI*C
/* Y=g]\%-PB
**Utility.java H8=:LF
*/ 7[UD;&\k
package NetFox; Tku6X/LF
"z;R"sv\
#dD0vYT&od
public class Utility { .U44p*I
`w`F-ke]I
3^xq+{\)
public Utility() %g{)K)$,ui
{ MvnQUZ
j>uu3ADd2
wG9aX*(n
} *'-t_F';
Nu\<Xr8
//线程睡眠 ByO?qft>u
public static void sleep(int nSecond) c!'\k,ma<9
{ CC;^J-h/
try{ SM2N3"\
Thread.sleep(nSecond); !pkIaCxs
} !n P4S)A
catch(Exception e) $mE3 FJP>
{ kFC*,
e.printStackTrace (); xI~AZ:m
} .Eb]}8/}E
} 8lGM>(:o
41s\^'^&
//日志 TA2ETvz^
public static void log(String sMsg) pek=!nZ
{ odC"#Rb
System.err.println(sMsg); ".waCt6
} }.Z`
[#RFdn<
X1o^MMpz(F
public static void log(int sMsg) `b]wyP
{ &;)B qqXc
System.err.println(sMsg); pe2:~}WB
} `j9\]50Z>
} {"%a-*@%
8iOHav4
x[Hx.G}5+
/* /<IWdy]$3
**TestMethod.java CCol>:8{P
*/ :]]x^wony~
package NetFox; .{*l,
ir>h3Zk
#ojuSS3
public class TestMethod { %7P]:G+Y\
l>`66~+s,`
_q4O2Fx0
public TestMethod() #+V4<o
{ ///xx/weblogic60b2_win.exe 1"75+Q>D
try{ T*PEUq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qsbV)c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); sQkijo.
SiteFileFetch fileFetch = new SiteFileFetch(bean); \Cj3jg
fileFetch.start(); ~<9e}J
} JGTsVa2
catch(Exception e){e.printStackTrace ();} !ehjLFS?_
DB-79U%W
?[m1?
} f!R7v|jP
{FKr^)g
"aCB}
public static void main(String[] args) oe2*$\?.
{ ;-@: }/
new TestMethod(); %=9o'Y,4
} +y8Y@e}>
} 1zH?.-
点击下载更多相关资料