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)); '?g&);4)k-
} 0Ng?U+6
for(int i=0;i<nEndPos.length-1;i++) Wh~,?}laj
{ 5)5yH bS
nEndPos = nStartPos[i+1]; 8si{|*;hL
} VT=gb/W6)a
nEndPos[nEndPos.length-1] = nFileLength; PsD)]V9%:
} 0rm(i*Q
} 0WYu5|
'2|P-/jU
Mc!LC .8
//启动子线程 (U_HX2f
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yK$aVK"
for(int i=0;i<nStartPos.length;i++) radP%W-U
{ 62y:i
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R0LWuE%eD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1&<o3)L:
nStartPos,nEndPos,i); axq~56"7E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MUGoW;}v)
fileSplitterFetch.start(); RDjw|V
} EuImj#Zl
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), He}?\C Bo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [-\U)>MY(p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .D\oKhV(
nEndPos = " + nFileLength); [IAk9B.\
// fileSplitterFetch[nPos.length-1].start(); b;#_?2c
$)BPtGMGo
rK`^A
//等待子线程结束 *<6dB#' J
//int count = 0; 0CK
//是否结束while循环 *c&OAL]
boolean breakWhile = false; LZ.Xcy
A1`6+8}o;b
lNtxM"G&
while(!bStop) 1i_%1Oip
{ \okv}x^L=Z
write_nPos(); a|.IAxJ
Utility.sleep(500); Q"GM3?
breakWhile = true; F`2h,i-9
j+{cc: h"X
7YK6e
for(int i=0;i<nStartPos.length;i++) >]C/ Q6
{ mg@Ol"2
if(!fileSplitterFetch.bDownOver) (@qS
{ AE~@F4MK
breakWhile = false; dqo-.,=
break; 1~3dX[&
} :Ea|FAeK8
} ;Bj&9DZd
if(breakWhile) a1/+C$ oB
break; k;2.g$)W[c
\8s:I+[HH
pV;0Hcy
//count++; v?}0h5
//if(count>4) $xq04ejJ
// siteStop(); OLm@-I*
} n;$u%2t2
yWE\)]9
D .LR-Z
System.err.println("文件下载结束！"); /!A"[Tyt
} kWy@wPqms
catch(Exception e){e.printStackTrace ();} b-#lKWso
} D6+3f#k6
"5O>egt
CR%h$+dzy
//获得文件长度 $Bl51VjN
public long getFileSize() UnYb}rF#%
{ }4H}*P>+
int nFileLength = -1; WBkx!{\z
try{ r]DU
URL url = new URL(siteInfoBean.getSSiteURL()); aR('u:@jHi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -)3+/4Q(
httpConnection.setRequestProperty("User-Agent","NetFox"); bZ OCj1
-1d*zySL
T!>hPg
int responseCode=httpConnection.getResponseCode(); )b>misb/
if(responseCode>=400) F4WX$;1
{ V45adDiZ
processErrorCode(responseCode); /x$JY\cq`
return -2; //-2 represent access is error kR^h@@'F"
} )T^wc:
[rK`BnJX
^blw\;LB
String sHeader; DI2e%`$
<eS/-W%n6
wVnmT94
for(int i=1;;i++) T]tu#h{ a
{ w?^[*_Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); VNIl%9:-l
//Utility.log(in.readLine()); D15-pz|Q
sHeader=httpConnection.getHeaderFieldKey(i); Zf<T`'_d
if(sHeader!=null) =>tkc/aa
{ b7I0R;Zj
if(sHeader.equals("Content-Length")) J5HK1
{ ]?wz.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hfyU}`]
break; !K}W.yv,
} `BG>%#
} %O"Whe
else ,+6u6
break; g52)/HM
} JJSE@$",\
} C58o="L3S
catch(IOException e){e.printStackTrace ();} 7Re\*[)T
catch(Exception e){e.printStackTrace ();} nqUnDnP2c
-.8K"j{N
|pWu|M _'
Utility.log(nFileLength); t&q~ya/C
m*N8!1Ot
~n%Lo3RiP
return nFileLength; ) 5$?e
} ~+Pe=~a[
eL(<p]
GN! R<9
//保存下载信息（文件指针位置） ;DYS1vGo
private void write_nPos() y_Urzgm(
{ F`x_W;\
try{ <f8j^
output = new DataOutputStream(new FileOutputStream(tmpFile)); =RRv& "2r
output.writeInt(nStartPos.length); ~M} K]Li
for(int i=0;i<nStartPos.length;i++) LPu*Lkx
{ k_wcol,W
// output.writeLong(nPos); 5 m-/N?c
output.writeLong(fileSplitterFetch.nStartPos); $`/UG0rdC
output.writeLong(fileSplitterFetch.nEndPos); w?|qKO
} ; YQB
output.close(); g@4~,
} [R%*C9Y d
catch(IOException e){e.printStackTrace ();} 4W*o:Y!
catch(Exception e){e.printStackTrace ();} K$/"I0YyI
} 'b}RFzEn
/NCN wAj7
GPhhg
//读取保存的下载信息（文件指针位置） l7^^MnkC
private void read_nPos() B;e<.M)e
{ Q8m%mJz~]
try{ j8[U}~*^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2-8Dc4H]r
int nCount = input.readInt(); 0NZ'(qf~9
nStartPos = new long[nCount]; >uq0}HB$a
nEndPos = new long[nCount]; M57<e`m
for(int i=0;i<nStartPos.length;i++) zm5PlG
{ Sqb>aj
nStartPos = input.readLong(); #!UJY%c~
nEndPos = input.readLong(); q6C`hVMl
} z7`|N`$Z#s
input.close(); NFEr ,n
} ~i?A!
catch(IOException e){e.printStackTrace ();} !'F1Ht
catch(Exception e){e.printStackTrace ();} ;)CN=J!
} 1@t.J>
ki@C}T5
H8? Y{H
private void processErrorCode(int nErrorCode) ui#nN
{ .Hqq!&
System.err.println("Error Code : " + nErrorCode); kG!hqj
} klFS3G
g*YA~J@
`Tyd1!~
//停止文件下载 1Xm>nF~
public void siteStop() 0'pB7^y
{ ]7W!f 2@
bStop = true; DAWF =p]
for(int i=0;i<nStartPos.length;i++) q 9xA.*
fileSplitterFetch.splitterStop(); ^#Q-?O
V^[&4
(W:@v&p
} $RYGAh
} }l$zZ>.\H
//负责部分文件的抓取 L f"!:]
**FileSplitterFetch.java [y'blCb
*/ N'EZJoH
package NetFox; U-1UWq
!fn%Q'S
H<i!C|AF
import java.io.*; E:**gvfq
import java.net.*; 8o%Vn'^t
+)q ,4+K%}
@#,/6s7?
public class FileSplitterFetch extends Thread { FD 8Lk
g&2g>]
?|W3RK;
String sURL; //File URL Bt@?l]Y
long nStartPos; //File Snippet Start Position zc)nDyn
long nEndPos; //File Snippet End Position [=jZP,b&),
int nThreadID; //Thread's ID Sj(>G;
boolean bDownOver = false; //Downing is over L QV@]z&
boolean bStop = false; //Stop identical -%fj-Y7y
FileAccessI fileAccessI = null; //File Access interface +CBN[/Z^i
'{ =F/q
CS~onf<xz
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !vu-`u~86
{ qfJ2iE|o2.
this.sURL = sURL; g{}<ptx]
this.nStartPos = nStart; 3R%JmLM+R9
this.nEndPos = nEnd; v%*don
nThreadID = id; ' abEY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k0V]<#h87
} o}KVT%}
t.;._'
SQK82/
public void run() :~8@fEKb{
{ +\_\53
while(nStartPos < nEndPos && !bStop) G^dp9A
{ r4iNX+h?V
UwS7B~
Q<V1`e
try{ AA,/AKikd
URL url = new URL(sURL); =L#&`s@)_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tb~E.Lm\
httpConnection.setRequestProperty("User-Agent","NetFox"); OjlX<y.
String sProperty = "bytes="+nStartPos+"-"; AH'c:w]~
httpConnection.setRequestProperty("RANGE",sProperty); sv%E5@
Utility.log(sProperty); 5<PNl~0
QjSWl,{ $D
P<&bAsje
InputStream input = httpConnection.getInputStream(); FNLS=4
//logResponseHead(httpConnection); `O2P&!9&
yD& Y`f#
zC)JOykI%
byte[] b = new byte[1024]; oc,I,v
int nRead; l([aKm#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) D )`(b
{ &\6},JN
nStartPos += fileAccessI.write(b,0,nRead); aeN #<M&$<
//if(nThreadID == 1) L)U*dY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ER9{D$
} BrSvkce
Q+Q"JU
$<)]~**K
Utility.log("Thread " + nThreadID + " is over!"); hq{{XQ
bDownOver = true; zL+t&P[\
//nPos = fileAccessI.write (b,0,nRead); Ip7#${f5M
} "!vY{9,
catch(Exception e){e.printStackTrace ();} n!Y_SPg
} v+{{j|x=
} ELnUpmv\
$k&v juB.
VV1sadS:S`
//打印回应的头信息 &D{!zF
public void logResponseHead(HttpURLConnection con) ZlC+DXg#S
{ tc`3-goX
for(int i=1;;i++) 4s:M}=]N
{ yN`hW&K
String header=con.getHeaderFieldKey(i); qVfn(rZ
if(header!=null) )N- '~<N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (OES~G
Utility.log(header+" : "+con.getHeaderField(header)); BR@gJ(2
else l<=k#d
break; tq}sedYhee
} 6v:L8t$"
} *wqR.n?
`R (N3
w_`;Mn%p
public void splitterStop() R=Lkf
{ |QbCFihn
bStop = true; l8+1{6xP
} pK{G2]OK{U
Vo{ ~D:)
jl7>
} =HMCNl
zBTxM
R3_;!/1
/* D?Ol)aj?
**FileAccess.java %<Qv?`B
*//文件访问(定位，写) U%1M?vT/
package NetFox; $ta"Ug.z
import java.io.*; h-Ks:pcR
\hlS?uD\
TGG=9a]m
public class FileAccessI implements Serializable{ OBlQ
$M-"az]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rFC9y o
RandomAccessFile oSavedFile; 23=wz%tF
long nPos; \[]BB5)8
jsV1~1:83
H 9/m6F
public FileAccessI() throws IOException FR50y+h^$
{ %y>*9$<pXe
this("",0); mrsN@(X0
} 3\ )bg R:
%|/\Qu
""V\hHdp
public FileAccessI(String sName,long nPos) throws IOException :&$v.#
{ I`@>v%0
oSavedFile = new RandomAccessFile(sName,"rw"); ;/23CFYM
this.nPos = nPos; j}@LiH'Q
oSavedFile.seek(nPos); qa:muW
} tQxAZ0B^
FDBNKQV
.gRb'
public synchronized int write(byte[] b,int nStart,int nLen) 9XS>;<"2
{ `tHF}
int n = -1; I)%bOK]
try{ [ot+EA
oSavedFile.write(b,nStart,nLen); -ImO y|
n = nLen; W>x.*K
} Zn|lL0b{q
catch(IOException e) Wa?\W&
{ ed/ "OgA
e.printStackTrace (); =y?Aeqq\fl
} N1:)Z`r
:=quCzG
NQ '|M
return n; }DvT6
} :W-xsw
$RRh}w\0^
vls+E o]
} b\NY!)B
bWCtRli}
#'#@H
/* 4 ;6,h6a
**SiteInfoBean.java &ML-\aSal
*/ s/;S2l$`
package NetFox; #cJ1Jj $
~-yq,x
z^KBV^n
public class SiteInfoBean { "[_gRe*2
!a%_A^t7
JsX}PVuL
private String sSiteURL; //Site's URL (c3O> *M
private String sFilePath; //Saved File's Path ,k:>Z&:
private String sFileName; //Saved File's Name D#>d+X$
private int nSplitter; //Count of Splited Downloading File &xC5Mecb*
HXB& 6
KpQ@cc
public SiteInfoBean() T}'*Gry
{//nSplitter的缺省值为5 d<cQYI4V
//default value of nSplitter is 5 1NN#-U
this("","","",5); &6\E'bBt
} A(C0/|#V
+I.{y
JVx-4?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [;C*9Nl
{ 0)vX
sSiteURL= sURL; 6D4u?P,
sFilePath = sPath; `Z@qWB<
sFileName = sName; w/ID yQ
this.nSplitter = nSpiltter; Jjx1`S*i
>ISBK[=H
)RT:u)N
} -{*QjP;K
UQT=URS
Og2w]B[
public String getSSiteURL() B1U7z1<
{ .T~Oc'wGo
return sSiteURL; $C{-gx+:
} ]PH'G>x
9$R}GK
vWYU'_=
public void setSSiteURL(String value) ^{O1+7d[.
{ _6sSS\
sSiteURL = value; V$MMK
} Ez^wK~
Q"GZh.m
Lnltt86
public String getSFilePath() 9iK%@k
{ 5.U|CL
return sFilePath; 0*/[z~Z-1
} H|d"45J_
)f`oCXh
eyByAT~W,
public void setSFilePath(String value) #ChF{mh
{ q+9c81b
sFilePath = value; mw${3j~&
} 7}fT7tsN
K3J,f2Cn$
? C6tYd
public String getSFileName() *b(nX,e
{ HhqNpU
return sFileName; c38ENf
} }}d,xI
WSx0o}
{ =IAS}
public void setSFileName(String value) E*UE?4FSw|
{ ]6?6 k4@
sFileName = value; @t#Ju1Y
} jH2_Ekgc;_
Cl!qdh6
oMb@)7
public int getNSplitter() kfs[*ku
{ Uj)`(}r
return nSplitter; zhC5%R &n/
} SGLU7*sfd
,D{D QJ(B
-j}zr yG-
public void setNSplitter(int nCount) f;a55%3c
{ Ob h@d|
nSplitter = nCount; /V E|FTs
} 89%#;C
} p y%RR*4#
&jE@i#
y-a3
/* = _/XFN
**Utility.java /G!M\teeF
*/ 39Tlt~Psz
package NetFox; 9h0Y">}`b
Au{J/G<W@
c[4I> "w
public class Utility { E Ks4N4k
M:.0]'[s5
t``q_!s}F
public Utility() "VQ7Y`,+
{ :Mnl1;oh
d`J~w/] `\
5P![fX|5
} v4X)R "jJ
yz^Rm2$f9
//线程睡眠 mW 'sdb
public static void sleep(int nSecond) yo!Y%9
{ kuo!}QFL
try{ 7toDk$jJRg
Thread.sleep(nSecond); eIt<da<G?
} 7E\k97#G
catch(Exception e) 2X@"#wIg
{ Hie
e.printStackTrace (); ?!$:I8T
} }9 I,p$
} o9c?)KQ
G9r~O#=gy
//日志 d&t,^Hj
public static void log(String sMsg) Fz@9 @
{ $3^Cp_p6
System.err.println(sMsg); ?4YLt|sn
} \vqqs
k[5:]5lp+
E8b:MY
public static void log(int sMsg) aJ$({ZN\#
{ jF0>wm
System.err.println(sMsg); c4(og|ifk
} trMwFpfu
} d2X?^
`]wk)50BVp
b_a6|
/* F%G} >xn
**TestMethod.java v8 pOA<s
*/ I"2*}v|
package NetFox; x5eSPF1
9}aEV 0 V|
Q4F&#^02y
public class TestMethod { Jju^4
&/-}`hIAT
Z90]I<a~
public TestMethod() Nd%j0lj
{ ///xx/weblogic60b2_win.exe j},3@TFh
try{ 9 f=~E8P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U*7x81v?j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b r\_
SiteFileFetch fileFetch = new SiteFileFetch(bean); IRT0
fileFetch.start(); n|eM}ymF+
} Nyl)B7/w
catch(Exception e){e.printStackTrace ();} 0@kL<\u
CX#d9 8\b
7(C:ty9
} 9i+`,r
q0VR&b`?>D
QfRo`l/V9
public static void main(String[] args) 63Z^ k(
{ !AN;
new TestMethod(); 3U%kf<m=
} U}DLzn|w
} J(w 3A)(
点击下载更多相关资料