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)); @11voD
} MnsnW{VGX
for(int i=0;i<nEndPos.length-1;i++) DRVvW6s
{ N2tvP+Z6D
nEndPos = nStartPos[i+1]; SJ7>*Sa(u$
} 9#6ilF:F
nEndPos[nEndPos.length-1] = nFileLength; ^B?koU l^
} 'eqvK|Uj:
} v(4C?vxhG
:"O=/p+*Us
Hv0sl+
//启动子线程 &H5 6mL{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zAB-kE\)
for(int i=0;i<nStartPos.length;i++) rf1nC$Sop
{ 7!JoP?!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qm]ljut
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), YQX>)'
nStartPos,nEndPos,i); T:.J9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hY'"^?OP
fileSplitterFetch.start(); r?/>t1Z
} ~w[zX4@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TJsT .DWW~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7@tr^JykO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ! 2Y, a
nEndPos = " + nFileLength); S%xGXmZ
// fileSplitterFetch[nPos.length-1].start(); 9fl !CG
9y]$c1
?QVD)JI*k
//等待子线程结束 &|E2L1
//int count = 0; "l +Jx|h\
//是否结束while循环 FT(EH
boolean breakWhile = false; XcfTE m
n{' [[2U
]r"{G*1Q 9
while(!bStop) 6lWO8j^BN
{ )If[pw@j
write_nPos(); ax>c&%vo
Utility.sleep(500); m_Fw;s/9
breakWhile = true; (c[h,>`@:
DD3J2J
zRE7 w:
for(int i=0;i<nStartPos.length;i++) o!\O)
{ wH${q@z_
if(!fileSplitterFetch.bDownOver) H8-,gV
{ HZK0Ldf
breakWhile = false; |g'sRTKJ
break; ryn)
} VJR'B={h
} W>DpDrO4ml
if(breakWhile) }=GyBnXu
break; dU&.gFw1
|[{;*wtv
ZXUe4@qfl
//count++; lP9I\Ge&
//if(count>4) D 1hKjB&
// siteStop(); +qz)KtJS
} +tV(8h4
EhD|\WLx!
$&e(V6A@
System.err.println("文件下载结束！"); }zobIfIF
} f$Ap\(.
catch(Exception e){e.printStackTrace ();} ?&GMp[
} VUnEI oKM
3tm z2JIb
q;>BltU
//获得文件长度 `riv`+J{s
public long getFileSize() q!H3JL
{ 0zTv'L
int nFileLength = -1; pJv?
try{ Qrt8O7&('
URL url = new URL(siteInfoBean.getSSiteURL()); \YKh'|04
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U1"t|KW8
httpConnection.setRequestProperty("User-Agent","NetFox"); R_1C+
G/8xS=
P5d@-l%}
int responseCode=httpConnection.getResponseCode(); {&<}*4D
if(responseCode>=400) a[$.B2U
{ 3w9 ]@kU
processErrorCode(responseCode); v]BQIE?R /
return -2; //-2 represent access is error fM|g8(TK,
} aW6+Up+G*
6m.Ku13;
\=@r1[d
String sHeader; Xou#38&p>
x ?V/3zW
.3U[@*b(
for(int i=1;;i++) (wlsn6h
{ 3N bn|_`(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tT8jC:oVa
//Utility.log(in.readLine()); @*uX[)
sHeader=httpConnection.getHeaderFieldKey(i); x<Zhj3
if(sHeader!=null) vaf9b}FL
{ fD~!t 8J
if(sHeader.equals("Content-Length")) 0o<qEo^
{ *3/7wSV:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gZjOlp
break; jSFN/C.9h
} |tg?b&QR
} [;=WnG
else .?p}:
break; i)2))C
} Vf?#W,5>=
} )RYnRC#O
catch(IOException e){e.printStackTrace ();} ;ULC|7rL
catch(Exception e){e.printStackTrace ();} j>o +}p?3I
?fmt@@]T?
y^AA#kk
Utility.log(nFileLength); 4Z}bw#
9 <KtI7
8`G{1lr4o
return nFileLength; |sFe:TX
} VM]IL%AN
M?B(<j1Ri
>fye^Tx
//保存下载信息（文件指针位置） ?*'$(}r3
private void write_nPos() %;Z bQ9
{ X[Ek'=}
try{ ,0Zn hS)kq
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8'lhp2#h
output.writeInt(nStartPos.length); gOyY#]g
for(int i=0;i<nStartPos.length;i++) @LKG\zYBu
{ y<`?@(0$
// output.writeLong(nPos); +^kxFQ(:
output.writeLong(fileSplitterFetch.nStartPos); =$8@JF'
output.writeLong(fileSplitterFetch.nEndPos); "F"_G
} {TncqA
output.close(); v{2DBr
} F4rKFMr
catch(IOException e){e.printStackTrace ();} P!y`$Ky&
catch(Exception e){e.printStackTrace ();} ~B!O~nvdQ
} |.C
)E:,V~< 8
v'Vt .m&9&
//读取保存的下载信息（文件指针位置） lmQ6X
private void read_nPos() h1XMx'}B
{ 5}eQaW48
try{ Yu^H*b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8rwYNb.P
int nCount = input.readInt(); ^%8qKC`Tt
nStartPos = new long[nCount]; ^5]uBOv
nEndPos = new long[nCount]; b(RBG
for(int i=0;i<nStartPos.length;i++) uyNJN
{ :wU_-{>>2
nStartPos = input.readLong(); S9p?*
nEndPos = input.readLong(); @ EmGexLPM
} T;!ukGoFP
input.close(); o-~~,n\
} (a `FS,M
catch(IOException e){e.printStackTrace ();} -2\ZzK0tM
catch(Exception e){e.printStackTrace ();} L}W1*L$;<
} YZGS-+
ejklpa ./
t<sNc8x
private void processErrorCode(int nErrorCode) &xiOTkqB
{ efjO8J[uk-
System.err.println("Error Code : " + nErrorCode); 4;C*Fa
} YOV :
{7?9jEj
yGvDn' m
//停止文件下载 Sty!atEWT
public void siteStop() cJ(BiL-uF
{ 8/3u/
bStop = true; >5;N64]!)
for(int i=0;i<nStartPos.length;i++) \+k, :8s/
fileSplitterFetch.splitterStop(); oYz!O]j;a
;1W6"3t-Y
5"JU?e59M
} o]Wz6L
} 7DtIVMiK
//负责部分文件的抓取 s`hav
**FileSplitterFetch.java 3J%V%}mD
*/ pkXv.D`
package NetFox; ^qxdmMp)l
/_V'DJV
GQN98Y+h
import java.io.*; ]9jZndgC
import java.net.*; D_d|=i
}[ ].\G\G
vwKw?Z0%J
public class FileSplitterFetch extends Thread { L=,OZ9aA
W h| L
<cYp~e%xIw
String sURL; //File URL eC~jgB
long nStartPos; //File Snippet Start Position :pwa{P
long nEndPos; //File Snippet End Position -!cIesK;<
int nThreadID; //Thread's ID 91up^
boolean bDownOver = false; //Downing is over 1otspOy
boolean bStop = false; //Stop identical p*|ah%F6N
FileAccessI fileAccessI = null; //File Access interface tBseqS3<
Ikj=`,a2B
*>k!hq;j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ic-IN~J-
{ )1f+ld%R
this.sURL = sURL; #{x5L^v>]
this.nStartPos = nStart; e*:}$u8a
this.nEndPos = nEnd; -#aZF2z
nThreadID = id; 9? 2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hK(tPl$
} P-'_}*wxi
e_/x&a(i8
?E<c[*F05
public void run() |3;(~a)%
{ uEx9-,!
while(nStartPos < nEndPos && !bStop) /b#q*x-b
{ KCUU#t|8V\
/s|{by`we4
CWi8Fv
try{ +K^h!d]
URL url = new URL(sURL); \D?:J3H*]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); , T\-;7
httpConnection.setRequestProperty("User-Agent","NetFox"); \iru7'S
String sProperty = "bytes="+nStartPos+"-"; 6Y1J2n"
httpConnection.setRequestProperty("RANGE",sProperty); zAs&%OjG
Utility.log(sProperty); 5M:D?9E+
rbyY8 bX
r`6:Q&&
InputStream input = httpConnection.getInputStream(); -7%X]
//logResponseHead(httpConnection); C>X|VP|C
eA=WGy@IcN
J8<J8x4
byte[] b = new byte[1024]; x<ax9{
int nRead; Ei5wel6!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :#u}.G
{ iW;i!,
nStartPos += fileAccessI.write(b,0,nRead); Zx{96G+1
//if(nThreadID == 1) ?Elg?)os
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T8XY fcc*h
} #@qN8J}R
SfB8!V|;
1] #9
Utility.log("Thread " + nThreadID + " is over!"); por/^=e{Y
bDownOver = true; Qi9-z'
//nPos = fileAccessI.write (b,0,nRead); ,9of(T(~
} |`O7nOM
catch(Exception e){e.printStackTrace ();} P)6lu8zQ
} S8vV!xO
} s8<gK.atl
7:Ztuc]
{fDTSr?/
//打印回应的头信息 UBZ9A
public void logResponseHead(HttpURLConnection con) B_^]C9C|
{ xT*d/Oaw
for(int i=1;;i++) Ne6}oQy(S`
{ < <Y}~N
String header=con.getHeaderFieldKey(i); d=3'?l`
if(header!=null) iwF9[wAft
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a|_p,_
Utility.log(header+" : "+con.getHeaderField(header)); 4Ysb5m)u
else r"{<%e
break; -YGbfd<wq
} aP-<4uGx
} oPQtGl p
Di5(9]o2
mD58T2Z
public void splitterStop() {~Tg7<\L
{ Vb|#MNf)
bStop = true; /JJw 6[N
} Uh6 '$0
GqKsK r2%
EbY,N:LK
} NjuiD].
0s#Kp49-
3_$w|ET
/* 4Xj4|Rw%
**FileAccess.java w.{&=WTr
*//文件访问(定位，写) +IFw_3$
package NetFox; s1N?/>lmB
import java.io.*; S>Yj@L
z+{,WHjo
J3RB]O_
public class FileAccessI implements Serializable{ _qwQ;!9
.Pndx%X9s
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )u%je~Vw
RandomAccessFile oSavedFile; )!bUR\
long nPos; kOwMs<1J
=T?}Nt
s^Nw%KAv
public FileAccessI() throws IOException [lzN !!B!
{ VosZJv=
this("",0); $ ,Ck70_
} B!]2Se2G
{$D,?V@%_
%]gTm7 =t
public FileAccessI(String sName,long nPos) throws IOException Cwa^"r3P1
{ x&sI=5l
oSavedFile = new RandomAccessFile(sName,"rw"); #p(h]T32
this.nPos = nPos; 4S"\~><
oSavedFile.seek(nPos); S^@S%Eg
} }_/Hdmmx
z /KK)u(q
B(a-k?
public synchronized int write(byte[] b,int nStart,int nLen) 2,2Z`X
{ ?liK\C2Z<
int n = -1; \J..*,'
try{ 1d"Z>k:mn
oSavedFile.write(b,nStart,nLen); {N2g8W:
n = nLen; \6n!3FLl
} q\Q{sv_
catch(IOException e) fqX"Lus `=
{ 6*4's5>?D
e.printStackTrace (); uzmk6G v
} lt^\
<?-YTY|
Q$& sTM
return n; gTgMqvt
} _It,%<3
mpAR7AG6
e0@6Pd
} Re:jVJgBz
H9h@sSg
q{s(.Uq$&
/* 9I1tN
**SiteInfoBean.java xq-17HKs
*/ *n]7
package NetFox; {Q+gZcu
Q9I j\HbA"
Y2xL>F
public class SiteInfoBean { 4h5g'!9-g
tz#gClo
l"\~yNgk
private String sSiteURL; //Site's URL jV.g}F+1m
private String sFilePath; //Saved File's Path aQI^^$9g
private String sFileName; //Saved File's Name ?)bS['^1)
private int nSplitter; //Count of Splited Downloading File <%xS{!'}
iXyO(w4D
0ye!R
public SiteInfoBean() QO"oEgB`+Z
{//nSplitter的缺省值为5 O+%WR
//default value of nSplitter is 5 (`SRJ$~f
this("","","",5); 66^ycZCH
} \Mg`(,kwe
K3\#E/Ox
J=pztASt
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _qbIh
{ jV(6>BAI_
sSiteURL= sURL; }g$(+1g
sFilePath = sPath; "NgoaG~!YO
sFileName = sName; :4^\3~i1X
this.nSplitter = nSpiltter; B||;'
}I@L}f5N
+~xnXb1
} ,f1q)Qf
qc#)!
p{PE@KO:
public String getSSiteURL() nFe%vu8a
{ Q}S_%I}u:
return sSiteURL; a_h]?5 :c
} {EdH$l>94
Y?ez9o:/#
S(\9T1DVe
public void setSSiteURL(String value) C/(M"j M
{ U^qt6$bK
sSiteURL = value; CRbdAqofV
} ;<0LXYL;
H3Se={5h\A
&Q}*+Y]G
public String getSFilePath() )[1)$-Ru
{ G;f/Tch
return sFilePath; rp5(pV7*
} ~tOAT;g}q
"zIFxDR#
-{`@=U
public void setSFilePath(String value) )P7)0c
{ :ujCr.
sFilePath = value; &YDK (&>
} 0euuT@_$
V'w@rc\XN
>a3p >2
public String getSFileName() YDGS}~m~Q
{ au,t%8AC
return sFileName; 6rS$yjTX!
} g@\fZTO
,RN:^5 p
QJ|ap4r
public void setSFileName(String value) GWvH[0
{ R0oKbs{
sFileName = value; ;W>Y:NCrp
} r!,}Z=cGe
y1=NF
C{2xHd/*
public int getNSplitter() 8BvonYt=8
{ inlk++Og
return nSplitter; :UJa&$)
} fr!Pj(Q1
]jpu,jz:
d6i6hcQE
public void setNSplitter(int nCount) ]:34kE}e5
{ h=_mNG>R)
nSplitter = nCount; T)\"Xj
} 9M"].~iNE
} ~n}k\s~|4
7^T^($+6s&
6=N`wi
/* WL{(Ob
**Utility.java a6kV!,.U
*/ JMdPwI
package NetFox; $wYFEz
e$Y[Z{T5
!a$ D4(`v
public class Utility { V(Yxh+KU
>c-fI$]
+/D>|loRC
public Utility() w{k)XY40sW
{ }h 3K@R
/.M+fr S
H:H6b
} KsrjdJx, '
NzKUtwnIz
//线程睡眠 |j3'eW&=
public static void sleep(int nSecond) Vb qto|X@
{ <)*2LBF@]
try{ g/CxXSv@0
Thread.sleep(nSecond); 1N2,mo?2
} 1 y}2+Kk
catch(Exception e) "7>>I D
{ 7=]i~7uy
e.printStackTrace (); 8P: Rg%0)
} a}SdW
} i@NqC;~;
n41@iK2l
//日志 7*DMVok:
public static void log(String sMsg) n}xhW'3hU=
{ E2L(wt}^
System.err.println(sMsg); Z>)][pL
} !6&W,0<
4x%(9_8{-
80M;4nH^5
public static void log(int sMsg) kqG0%WtQ
{ .lhn;*Yi
System.err.println(sMsg); "!K'A7.^
} j'i0*"x
} >\ST-7[^L
l8K5k:XCU3
`IINq{Zk
/* ,%bhyww<
**TestMethod.java Cc?TSZ8[
*/ M\b")Tu{0
package NetFox; h;lirvO|
;DnUQj
7 1W5.!
public class TestMethod { j\RpO'+}
S'~o,`xy
n3MWs);5
public TestMethod() 6{d6s#|%
{ ///xx/weblogic60b2_win.exe t4Z
try{ 6pE :A@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,~zj=F
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C9S@v D+
SiteFileFetch fileFetch = new SiteFileFetch(bean); /W#O +
fileFetch.start(); nRhrWS
} y'ja< 1I>
catch(Exception e){e.printStackTrace ();} "HM{b?N
H]<]^Zmjy
8|twV35
} )_zlrX
1-I Swd'u
R4%P:qM
public static void main(String[] args) q&'Lbxc>c
{ lhC6S'vq
new TestMethod(); dEM?~?
} 2=PBxDs;
} +?RGta'%k
点击下载更多相关资料