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)); StuDtY
} \PB~6
for(int i=0;i<nEndPos.length-1;i++) 044*@a5f
{ {%;KkC8=R
nEndPos = nStartPos[i+1]; jW-j+WGSM
} (SlrV8;
nEndPos[nEndPos.length-1] = nFileLength; gB?~!J?
} ~CB6+t>
} iEf6oM
Eb<iR)e H=
= ?hx+-'
//启动子线程 t $+46**
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; OgTE^W@
for(int i=0;i<nStartPos.length;i++) Ur]~>-Z
{ ]d@@E_s]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~4~-^ t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Sr`gQ#b@r}
nStartPos,nEndPos,i); ;=.QT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _ .%\czO
fileSplitterFetch.start(); M7(vI4V
} 0Up@+R2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G/Xa`4"_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2\z"6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Pe !eID8
nEndPos = " + nFileLength); i7[CqObzc
// fileSplitterFetch[nPos.length-1].start(); Q\~4J1
[k9aY$baT^
$z+iB;x
//等待子线程结束 [z:bnS~yiD
//int count = 0; $3!j1
//是否结束while循环 Aghcjy|j
boolean breakWhile = false; cmIAWFj-)e
^#R-_I
3d.JV'C'c
while(!bStop) @awaN
{ _|ucC$*
write_nPos(); WRJ+l_81
Utility.sleep(500); ?zKVXK7}0
breakWhile = true; Xz=MM0o
w49Wl>M
v?yHj-
for(int i=0;i<nStartPos.length;i++) )T:{(v7 d`
{ OH28H),}
if(!fileSplitterFetch.bDownOver) &DFe+y~PR
{ $;_'5`xs
breakWhile = false; S#X$QD
break; 2oAPJUPOJ
} daaEN(
} QY2!.a^q
if(breakWhile) sa`7_KB
break; KLXv?4!
l{4=La{?j
^)b*"o
//count++; buRXzSR
//if(count>4) )Xa`LG=|
// siteStop(); X9nt;A2TU+
} <GShm~XD2
j8@YoD5o
DFs J}` $
System.err.println("文件下载结束！"); uKqN
} J! >HT'M
catch(Exception e){e.printStackTrace ();} )}?'1ciHI
} &j/ WjZPF
+b]g;
M"K$81
//获得文件长度 :eI.E:/'
public long getFileSize() QzIK580%t
{ 4T6dju
int nFileLength = -1; }Xs=x6Mj
try{ j?6%=KuX<
URL url = new URL(siteInfoBean.getSSiteURL()); v'.?:S&m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Xt/T0.I
httpConnection.setRequestProperty("User-Agent","NetFox"); iLy}G7h
UUv&X+Y
3skq%;%Wsk
int responseCode=httpConnection.getResponseCode(); vI]| W
if(responseCode>=400) r]km1SrS
{ PDX^MYoN
processErrorCode(responseCode); O!sZMGF$p
return -2; //-2 represent access is error .*D~ .!
} E/(:\Cm^
/Z>#lMg\.
:9c QK]O6
String sHeader; KEsMes(*
~,Q+E8
K(Otgp+zb
for(int i=1;;i++) #HB]qa
{ !l_1r$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _p7c<$;
//Utility.log(in.readLine()); p[&'*"o!/
sHeader=httpConnection.getHeaderFieldKey(i); IQdiVj
if(sHeader!=null) GFx>xQk
{ v4(!~S
if(sHeader.equals("Content-Length")) ~LHG
{ Qm,|'y:Tg
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^MUtmzh
break; Ol"p^sqwj
} gOO\` #
} .0#?u1gXsX
else b}o^ ?NtA
break; 6+FmYp
} mN_RB{g{
} 1I KDp]SN
catch(IOException e){e.printStackTrace ();} iO3@2J
catch(Exception e){e.printStackTrace ();} Tm[IOuhM'?
j$zw(EkN
,jbj-b(
Utility.log(nFileLength); vhZpYW8
d/- f]
O} QTg
return nFileLength; +=Crfvt
} ,/|"0$p2x
Q9X_aB0
GKtG#jZ&
//保存下载信息（文件指针位置） sBq @W4
private void write_nPos() qJVW :$1q
{ <"AP&J'H
try{ J^ryUOo}b
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4'?kyTO~
output.writeInt(nStartPos.length); Z|uUE
for(int i=0;i<nStartPos.length;i++) e!ar:>T
{ V;~W,o!
// output.writeLong(nPos); D^I%tn=F
output.writeLong(fileSplitterFetch.nStartPos); Wze\z
output.writeLong(fileSplitterFetch.nEndPos); }Hrm/Ni
} Dx/?0F7V
output.close(); S*IF/ fu
} `K~300-hOb
catch(IOException e){e.printStackTrace ();} 1N1MD@C?P
catch(Exception e){e.printStackTrace ();} ; @-7'%(C
} zy8W8h(?
d>)*!l2,C
R.!'&<Svq
//读取保存的下载信息（文件指针位置） Q~#udEajI
private void read_nPos() |OUr=b
{ 65\'(99yU
try{ 55Y BO$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7<mY{!2iF?
int nCount = input.readInt(); h:<pEL
nStartPos = new long[nCount]; !BP/#
nEndPos = new long[nCount]; "D2`=D!+
for(int i=0;i<nStartPos.length;i++) ,*Tf9=z
{ !TVlsm
nStartPos = input.readLong(); G 2+A`\]
nEndPos = input.readLong(); hoD (G X
} ZTVX5"#Q
input.close(); 4W*52*'F,
} S j)&!
catch(IOException e){e.printStackTrace ();} 0j7W\'!t
catch(Exception e){e.printStackTrace ();} BYyR-m
} p./zW )7+
s6lo11
EQ-r
private void processErrorCode(int nErrorCode) T' %TMA
{ vtKQvQ
System.err.println("Error Code : " + nErrorCode); :&HrOdz
} _)yn6M'Dt
vXAO#'4tm%
6UG7lH!M
//停止文件下载 (g`G(K_
public void siteStop() d0"Hu^]
{ %]h5\%@w
bStop = true; c]v$C&FX
for(int i=0;i<nStartPos.length;i++) (xBS~}e
fileSplitterFetch.splitterStop(); |yx]TD{~P
Q.>@w<[!L
<[@AMdS
} O[U^{~iM
} |`1lCyV\tE
//负责部分文件的抓取 mQhI"3!f
**FileSplitterFetch.java 9i*t3W71]
*/ casva;
package NetFox; U}~SY
z8G1[ElY
}KEyJj3"DA
import java.io.*; b lP@Cn2
import java.net.*; k(pI5N}pJZ
C}<j8a?
3vfm$sx@
public class FileSplitterFetch extends Thread { {~_X-g5|]
>k"Z'9l
7#SXqyP[
String sURL; //File URL y4PR&^l?g
long nStartPos; //File Snippet Start Position 'c*Q/C;
long nEndPos; //File Snippet End Position OS;qb:;
int nThreadID; //Thread's ID _HW~sz|
boolean bDownOver = false; //Downing is over !}<d6&!py
boolean bStop = false; //Stop identical S}f3b N
FileAccessI fileAccessI = null; //File Access interface rG|lRT3-K
rkugV&BhV
'G;y!<a
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9E5Ec~l
{ !K-lO{Z^
this.sURL = sURL; wmAZ {
this.nStartPos = nStart; 0}C> e`<'
this.nEndPos = nEnd; 0+L:+S
nThreadID = id; D1rXTI$$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {4J:t_<nKO
} zP$0B!9
IL;JdIa
kU{+@MA;
public void run() j*+[=X/
{ Tw*:Vw
while(nStartPos < nEndPos && !bStop) YRa{6*M
{ HX%lL}E
F7P?*!dx
cH%qoHgx
try{ rp^=vfW
URL url = new URL(sURL); 'APtY;x^{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bnHQvCO3$
httpConnection.setRequestProperty("User-Agent","NetFox"); _<s[HGA`z
String sProperty = "bytes="+nStartPos+"-"; un([3r
httpConnection.setRequestProperty("RANGE",sProperty); a9]F.Jm
Utility.log(sProperty); }N[|2nR'
r@b M3V_o
W^#HR
InputStream input = httpConnection.getInputStream(); {9:[nqX
//logResponseHead(httpConnection); B3|h$aKC
P'%#B&LZo
dO]N&'P7
byte[] b = new byte[1024]; R+{QZ'K.qg
int nRead; {w:*t)@j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U4)x"s[CP
{ <LL+\kfTZO
nStartPos += fileAccessI.write(b,0,nRead); Sk7l&B
//if(nThreadID == 1) nb-]fa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $WmB__
} ^/@Z4(E
t6u>_She
;e Iqxe>
Utility.log("Thread " + nThreadID + " is over!"); x-27rGN
bDownOver = true; &O8vI,M
//nPos = fileAccessI.write (b,0,nRead); riw0w
} aT|SKb`
catch(Exception e){e.printStackTrace ();} ]nPfIBoS
} :{sy2g/+
} >=Bl/0YH
lw+Y_;
ASGV3r(
//打印回应的头信息 {zzc/!|
public void logResponseHead(HttpURLConnection con) X!H[/b:1O
{ @jh\yjrW
for(int i=1;;i++) ]JDKoA{S0
{ <14,xYpE
String header=con.getHeaderFieldKey(i); ^4MRG6G
if(header!=null) Q/D?U[G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); TwPpZ@
Utility.log(header+" : "+con.getHeaderField(header)); D)shWJRlvW
else wavyREK
break; a(.q=W
} &[ oW"Q{
} ?e=3G4N
oF'_x,0
pQ~Y7
public void splitterStop() s Zn@ye^
{ N"/J1
bStop = true; Pgug!![
} `r#]dT[g
hk*@<ff
1fgO3N
} i ZU1w7Z
C2e.RTxc
ZG(.Q:1
/* <TN+-)H6
**FileAccess.java *2,tGZ
*//文件访问(定位，写) 7QSrC/e
package NetFox; ,:[\h\5m
import java.io.*; 0G; b+
gvzBV +3'
w-{a>ZU0
public class FileAccessI implements Serializable{ ~ eNKu
Q*jNJ^IW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `@<>"ff#F
RandomAccessFile oSavedFile; y@XE! L
long nPos; 9U]3B)h%m
TmviYP gb
(V(8E%<c
public FileAccessI() throws IOException mETGYkPUa
{ C[ma!he
this("",0); hqDnmzG
} \u4`6EYF?
yC&u^{~BC
+HDfEo T
public FileAccessI(String sName,long nPos) throws IOException =Ju%3ptH0
{ 5,_DM
oSavedFile = new RandomAccessFile(sName,"rw"); JnE\z*NB
this.nPos = nPos; w;b;rHAZ\
oSavedFile.seek(nPos); (e"\%p`
} P>}OwW
bU4l|i;j
Z Jgy!)1n
public synchronized int write(byte[] b,int nStart,int nLen) ;$.^
{ ee2k..Tq#
int n = -1; N({0"7
try{ BbIg]E/G
oSavedFile.write(b,nStart,nLen); q2+`a;_S
n = nLen; MA1y@
} sq rY<@%
catch(IOException e) S7v# `#
{ #1)#W6 h\
e.printStackTrace (); 4`Ib wg6"B
} V=d~}PJ>
~'#yH#o
M o?y4X
return n; |=u }1G?
} rtxG-a56Q
\yhj{QS.k
1xTNrLW
} FZBdQhYF
L#k`>Qn2
]q`'l_O
/* cj;k{Moc
**SiteInfoBean.java $Wn!vbL
*/ @ JfQ}`
package NetFox; GT 5J`
b3.}m[]
?Gnx!3Q
public class SiteInfoBean { 6s.>5}M!
7`J= PG$A
]?*'[
private String sSiteURL; //Site's URL wh2Ljskda8
private String sFilePath; //Saved File's Path b"JX6efnN
private String sFileName; //Saved File's Name GHRr+
private int nSplitter; //Count of Splited Downloading File XXg~eu?
4+B&/}FDLo
tk\)]kj
public SiteInfoBean() ;9;jUQ]MyG
{//nSplitter的缺省值为5 bLsN?_jy
//default value of nSplitter is 5 7pO/!Lm
this("","","",5); >&[q`i{
} O0_kLH$.
2TccIv
E#n=aY~u-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /?%1;s:'
{ *v#Z/RrrA
sSiteURL= sURL; T+j-MR}{\
sFilePath = sPath; &BxZ}JH=k
sFileName = sName; je;|zfe]
this.nSplitter = nSpiltter; ^wlo;.8Y
cqG&n0zb
K3^2;j1F Q
} LEd@""h
_ SJFuv/
G-[.BWQ
public String getSSiteURL() -Oplk*
{ sTmdoqTK!
return sSiteURL; ` InBhU>
} p~yGp]yJ9
YBupC!R
9jI5bi)
public void setSSiteURL(String value) b^q%p1
{ `^df la
sSiteURL = value; RjxFlKs8
} PTH'-G
, Y^GQ`~#
lho0Xy gn
public String getSFilePath() FT6~\9m(
{ 2*@@Bw.XA
return sFilePath; 5H2Ugk3
} ],F@.pg
,zOv-pH
y_M,p?]^,
public void setSFilePath(String value) P?|>, \t
{ 5ajd$t
sFilePath = value; tHmV4H$
} "R0(!3
1StaQUB
b[^|.>b
public String getSFileName() 8,L)=3m-
{ 4W<8u(
return sFileName; JIXZI\Fk
} ~\OZEEI
%?PRBE'}'
ldWrv7.P
public void setSFileName(String value) i#%!J:_=
{ '3]M1EP
sFileName = value; k;f%OQsF_
} M.K%;j`
$Dm|ol.Z
A>C8whx
public int getNSplitter() (/jZ&4T
{ !h70<Q^
return nSplitter; X< 4f7;]O
} tY- `$U@
aucG|}B
% U|4%P
public void setNSplitter(int nCount) [orS-H7^
{ )\+1*R|H}
nSplitter = nCount; "H|hN
} lNx:_g:SrZ
} *n_7~ZX
|W*i'E
Vi>`g{\
/* <KrfM
**Utility.java b,lIndj#
*/ 8F/JOtkGMt
package NetFox; 64l(ru<
;uaZp.<um&
MXs]3M
public class Utility { I`q"
6]fz;\DgP
.&rL>A2U
public Utility() N4u-tlA
{ h 6juX'V
;oWak`]f
C!^[d
} B qcFbY
[4b_`L
//线程睡眠 -5GRit1q?
public static void sleep(int nSecond) 7;SI=
{ '5}@#Mi
try{ jd+U+8r
Thread.sleep(nSecond); 1? Im"
} <CN+VXF
catch(Exception e) -aQf(=
{ Lz=GA?lk[\
e.printStackTrace (); j'q Iq;y
} 7i88iT
} Q6hWHfS
dReJ;x4
//日志 $kxP{0u
public static void log(String sMsg) `:kI@TPI_C
{ HB9|AQ4K
System.err.println(sMsg); ~JTp8E9kw
} l [ Navw
/EV _Y|(-
O_^;wey0}?
public static void log(int sMsg) frUO+
{ nE=,=K~
System.err.println(sMsg); A;gU@8m
} '<Jqp7$dL
} 1(jDBP!8
c63yJqiW
!1xX)XD4y
/* M5c~-}Ay
**TestMethod.java UJk/Lxv
*/ -P-&]F5
package NetFox; -P We
{qb2!}FQ
Kq;s${ |G
public class TestMethod { lR0WDJv
O_^t u?x
_qsg2e}n
public TestMethod() fl o9iifZ
{ ///xx/weblogic60b2_win.exe -HUlB|Q8r
try{ aLO'.5 ~^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %OAvhutS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (!0fmL
SiteFileFetch fileFetch = new SiteFileFetch(bean); %SJFuw"
fileFetch.start(); P:fcbfH+
} -gVsOX0
catch(Exception e){e.printStackTrace ();} I3d!!L2ma
LuvRxmQ`
;lc/FV[/
} >6A8+=
r"&VG2c0K
.?)gn]#
public static void main(String[] args) o((!3H{D
{ Qgxpq{y
new TestMethod(); _7b' i6-
} y8$I=
} sU0W)c;
点击下载更多相关资料