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)); "?n;dXYSi
} cAQ_/>
for(int i=0;i<nEndPos.length-1;i++) h(4&!x
{ l2h1CtAU
nEndPos = nStartPos[i+1]; j0.E!8Ae{
} v1aE[Q
nEndPos[nEndPos.length-1] = nFileLength; 4R&e5!
} |e+r|i]
} 'u84d=*l
IA3m.Vxj ^
'mm~+hp
//启动子线程 I*`;1+`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %h9'kJzNk
for(int i=0;i<nStartPos.length;i++) FE4P EBXvu
{ xhw0YDGzf
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >ca w :
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3:mZ1+
nStartPos,nEndPos,i); T/nG\WZbZn
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~LU$ no^
fileSplitterFetch.start(); ('oA{,#L
} ~gA^tc3G
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?d5_{*]+v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9?Q0O\&uP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,(v=ZeI
nEndPos = " + nFileLength); 4OTrMT$y
// fileSplitterFetch[nPos.length-1].start(); 4sM9~zC5
SpA-E/el
O3En+m~3n)
//等待子线程结束 w%uM=YmuT
//int count = 0; kj]m@mS[
//是否结束while循环 f|NWn`#bY
boolean breakWhile = false; $l/w.z
)=Ens=>Z
FC q&-
while(!bStop) g=Bge)
{ Y5R|)x
write_nPos(); N+CcWs!E
Utility.sleep(500); >)8<d3m
breakWhile = true; N D1'XCN
Nc\jA=
' )~G2Ys
for(int i=0;i<nStartPos.length;i++) -/LB-t
{ V1 {'d[E*
if(!fileSplitterFetch.bDownOver) -oB`v'
{ Mp_SL^g|
breakWhile = false; kPezR: 31
break; 7z9[\]tt
} K'zBDrkW-x
} (&oT6Ji
if(breakWhile) <hB~|a<#
break; Ehf3L |9
%QKRl5RM-
nO7#m~
//count++; NJTC+`Hm
//if(count>4) 32ae? d
// siteStop(); J t,7S4JL
} ?L~Z]+-
@lP<Mq~]
Eqg(U0k0
System.err.println("文件下载结束！"); ~7!J/LHg
} =De%]]>
catch(Exception e){e.printStackTrace ();} 7"r7F#D=G
} >,`/ z
Z3G>DF:$
QY2!.a^q
//获得文件长度 ~$f+]7
public long getFileSize() <v"C`cga
{ !+.|T9P
int nFileLength = -1; 3R?7&oXvH
try{ zVs_|x="
URL url = new URL(siteInfoBean.getSSiteURL()); DFs J}` $
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _VR Sdr5
httpConnection.setRequestProperty("User-Agent","NetFox"); )}?'1ciHI
ke~O+]
>Ge&v'~_|
int responseCode=httpConnection.getResponseCode(); }VE[W
if(responseCode>=400) F]W'spF,
{ >#R<*?*D}
processErrorCode(responseCode); v'.?:S&m
return -2; //-2 represent access is error r M'snW)
} GFx>xQk
/g'F+{v
?D\6CsNp(2
String sHeader; Ol"p^sqwj
,g{`M]Ov
PR~ho&!
for(int i=1;;i++) mN_RB{g{
{ /l0\SVwa>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .BlGV2@^#
//Utility.log(in.readLine()); c^UG}:Y
sHeader=httpConnection.getHeaderFieldKey(i); ;hmy7M1%
if(sHeader!=null) \x)T_]Gcm
{ z)q9O_g9
if(sHeader.equals("Content-Length")) lW?}jzuo
{ UL(R/yc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [1dlV/
break; "m _wYX
} zfO0+fMH
} >I8R[@
else +Ld4e]
break; +l2{EiQw
} $=TFTSO
} |JSj<~1ki
catch(IOException e){e.printStackTrace ();} ;a XcGa
catch(Exception e){e.printStackTrace ();} &2Q4{i
n4Ry)O[.
UOZ"#cQ
Utility.log(nFileLength); 7*M+bZ`x
My76]\Psh
.4Jea#M&x
return nFileLength; zdzTJiY2[Z
} 4W*52*'F,
>jME == U0
dG'aJQw
//保存下载信息（文件指针位置） ,H2[["1DH
private void write_nPos() 81O`#DfZ
{ 'mp@!@_
try{ y-)|u:~h
output = new DataOutputStream(new FileOutputStream(tmpFile)); r;g[<6`!S
output.writeInt(nStartPos.length); DFQp<Eq]7
for(int i=0;i<nStartPos.length;i++) UIi;&[
{ eqb8W5h'
// output.writeLong(nPos); ']WS@MbJ
output.writeLong(fileSplitterFetch.nStartPos); 7](,/MeGG
output.writeLong(fileSplitterFetch.nEndPos); WolkW:(Cg
} "G].hKgbk*
output.close(); l<>syHCH;L
} g'ha7~w(p
catch(IOException e){e.printStackTrace ();} 2w>WS#
catch(Exception e){e.printStackTrace ();} 0/S|h"-L
} ~,WG284
epI&R)]
T!0o(Pp<
//读取保存的下载信息（文件指针位置） 'G;y!<a
private void read_nPos() l=ehoyER
{ u9ObFm$7
try{ }:<`L\8q\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m-Q!V+XQp
int nCount = input.readInt(); E #q gt9
nStartPos = new long[nCount]; S {oW
nEndPos = new long[nCount]; +:k Iq
for(int i=0;i<nStartPos.length;i++) v W=$C
{ iZ}Afj
nStartPos = input.readLong(); Ezsb'cUa(
nEndPos = input.readLong(); _uwM%M;
} GOrDDp
input.close(); -< D7
} `G7LM55
catch(IOException e){e.printStackTrace ();} sA$x2[*O
catch(Exception e){e.printStackTrace ();} 1W3+ng
} <LL+\kfTZO
p}H:t24Cr5
}p,#rOX:A
private void processErrorCode(int nErrorCode) 9<0TF+}>
{ ^{Wx\+*!
System.err.println("Error Code : " + nErrorCode); " kp+1sG8
} @uA=v/>+
#J=^CE
5&A{IN
//停止文件下载 }_Y&kaM
public void siteStop() (bhMo^3/*
{ [0c7fH`8V
bStop = true; TwPpZ@
for(int i=0;i<nStartPos.length;i++) )/4eT\=
fileSplitterFetch.splitterStop(); 6sceymq
mnzB90<
9;2{=,
} zXX=WH
} #/N;ScyUJT
//负责部分文件的抓取 wFbw3>'a9
**FileSplitterFetch.java ohEIr2
*/ ycD.X"
package NetFox; kPRG^Ox8e
3R|UbG`
0G; b+
import java.io.*; hW<TP'Zm*
import java.net.*; $Gs9"~z?;
A4K8DP
6(pa2
public class FileSplitterFetch extends Thread { ]v2%hX
\]Bwib%h
op8[8pt%
String sURL; //File URL yC&u^{~BC
long nStartPos; //File Snippet Start Position =Ju%3ptH0
long nEndPos; //File Snippet End Position _a]0<Vm C0
int nThreadID; //Thread's ID 7&`Yl[G
boolean bDownOver = false; //Downing is over \d)HwO
boolean bStop = false; //Stop identical Mq~g+` '
FileAccessI fileAccessI = null; //File Access interface ,7:?Du}
Vq&}i~
zp'Vn7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~o8
{ MV.&GUez{
this.sURL = sURL; h"}c_lY9
this.nStartPos = nStart; ~'#yH#o
this.nEndPos = nEnd; SX)o0v+
nThreadID = id; uqHI/4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @1vpkB~ w
} 0/5{v6_rG
o}b_`O
mS?W+jy%
public void run() RW`+F|UbE
{ IY,n7x0d
while(nStartPos < nEndPos && !bStop) 3D-VePM=`
{ ,p' ;Xg6ez
5~FXy{ZIH
"?=$(7uc
try{ X1XmaO%A
URL url = new URL(sURL); yPoa04!{=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4N(iow4
httpConnection.setRequestProperty("User-Agent","NetFox"); {d '>J<Da
String sProperty = "bytes="+nStartPos+"-"; @bIZ0tr4
httpConnection.setRequestProperty("RANGE",sProperty); {k uC+~R
Utility.log(sProperty); y=&^=Zh[
/5Tp)h|
!B/5@P
InputStream input = httpConnection.getInputStream(); kYZj^tR
//logResponseHead(httpConnection); O`f[9^fN
PTH'-G
p5Wz.n.<'
byte[] b = new byte[1024]; |xFSGrC
int nRead; D+xPd<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (mgv:<c;BA
{ x"~gulcz
nStartPos += fileAccessI.write(b,0,nRead); glomwny
//if(nThreadID == 1) H`OJN.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i#%!J:_=
} ;Dp<|n
a{\<L/\
(/jZ&4T
Utility.log("Thread " + nThreadID + " is over!"); %I#[k4,N
bDownOver = true; j>)yV@g/
//nPos = fileAccessI.write (b,0,nRead); T:g=P@
} jg3T1ROL
catch(Exception e){e.printStackTrace ();} &+")~2 +
} Cznp(z
} /-Y.A<ieN8
;uaZp.<um&
I`q"
//打印回应的头信息 o{OY1 ;=6
public void logResponseHead(HttpURLConnection con) QBLha']'%
{ eVRjU
for(int i=1;;i++) -op(26:W<
{ Lz=GA?lk[\
String header=con.getHeaderFieldKey(i); )<vuv9=k\%
if(header!=null) 9Bi{X_.9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }o7"2hht
Utility.log(header+" : "+con.getHeaderField(header)); nZ/pi$7
else .NT9dX
break; :NXM.@jJ="
} %<@x(q
} T*rx5*:o
!@9G9<NK
u9D#5NvGs
public void splitterStop() ok(dCAKP
{ Kd;)E 9Ti
bStop = true; A3Oe=rB
} ~JG\b?s
>M^4p
xH>2$ ;f
} HD153M,
-p[!CI
FwqaWEk
/* evGUl~</~
**FileAccess.java LyG&FOf?
*//文件访问(定位，写) agj_l}=gO
package NetFox; eKW^\
import java.io.*; 1i/&t[
l'twy$V4|~
T1i}D"H %
public class FileAccessI implements Serializable{ I8Q!`KJ
Xhp={p;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 lky5%H
RandomAccessFile oSavedFile; \`Ow)t:
long nPos; PIM4c
#}S<O_
T.pc3+B8N
public FileAccessI() throws IOException Y>Fh<"A|$
{ Eal*){"<,?
this("",0); ,racmxnv
} RiiwsnjC
!![HR6"Q
u#nM_UJe
public FileAccessI(String sName,long nPos) throws IOException 'f-8P
{ og`K!d~
oSavedFile = new RandomAccessFile(sName,"rw"); %gEgpJd
this.nPos = nPos; U# U*^#
oSavedFile.seek(nPos); U?=-V8#M|
} mOfTq] @B
=XFyEt
d8.A8<wUr
public synchronized int write(byte[] b,int nStart,int nLen) A5go)~x\
{ X=jHH=</
int n = -1; i,!tu
try{ #oJ%i+V
oSavedFile.write(b,nStart,nLen); }6!m Q
n = nLen; E7 P'}
} J*4T|#0
catch(IOException e) '$5Qdaj
{ t&Jrchk
e.printStackTrace (); ou=33}uO
} (?1/\r
/kAbGjp0
DLO2$d
return n; jIck!
} ?*&5`Xh
`\yQn7 Oq
q9(Z9$a(\
} La$?/\Dv)
RV),E:?
B^Hhrz!
/* v.F|8 cG
**SiteInfoBean.java %R P\,|
*/ |?t}7V#[
package NetFox; !+(H(,gI
H` h]y
BBa!le9P
public class SiteInfoBean { Hb\['VhzM
KM/c^a4V
OlM3G^1e1
private String sSiteURL; //Site's URL WmuYHEU
private String sFilePath; //Saved File's Path 5=Il2
private String sFileName; //Saved File's Name Bz? (?fyd
private int nSplitter; //Count of Splited Downloading File C);I[H4Yfw
cToT_Mk
8aTo TA7JA
public SiteInfoBean() ijmGk:L(
{//nSplitter的缺省值为5 wZt2%+$6m
//default value of nSplitter is 5 |a=7P
this("","","",5); MP~+@0cv
} HqXS-TG
D{6<,#P{w
=g?k`vp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3x>Y
{ Z<#h$XUA
sSiteURL= sURL; ucFfxar"
sFilePath = sPath; DJ`xCs!R
sFileName = sName; c9Q_Qr0'
this.nSplitter = nSpiltter; ;_m;:<
{ T?1v*.[
DK1{Z;Z
} G,6 i!M
tc{Qd&"(
'?T<o
public String getSSiteURL() [<X ~m
{ 1V-sibE
return sSiteURL; oE)xL%*
} '`j MNKn\
sU/vXweky"
goc; .~?
public void setSSiteURL(String value) fYlqaO4[
{ *A0*.>@N
sSiteURL = value; nI/kX^Pd
} S7j U:CLJ
oWq]\yT<`
r`e6B!p
public String getSFilePath() M,we,!B0
{ *!yA'z<
return sFilePath; @_?Uowc8
} #)4p,H
I(<Trn
!w/]V{9`X
public void setSFilePath(String value) @XVx{t;g2
{ 6\? 2=dNX
sFilePath = value; O6ltGtF
} ? 3oUkGfn
AvB21~t&]
Nx!7sE*b$1
public String getSFileName() f/{ClP.
{ d"S\j@
return sFileName; SVPksr
} TJ|do`fw>
dJ~Occ1~r
10_>EY`
public void setSFileName(String value) uEkGo5
{ 'tt4"z2
sFileName = value; /< Dtu UM
} k<RaC=
)Jh:~9L%='
IV%Rph>d
public int getNSplitter() !E^\)=E)P
{ ycf)*0k
return nSplitter; hLT?aQLx
} $)6x3&]P
L#fK ,r8
+y\o^w4sT
public void setNSplitter(int nCount) Dy{lgT0k
{ f,Am;:\|
nSplitter = nCount; HT6$|j
} O"wo&5b_
} hJ75(I *j
v=DC3oh-
P!lfk:M^;
/* |{MXDx
**Utility.java NMzq10M=6
*/ :.(A,
package NetFox; '_ys4hz}
B/Ltb^a
i;\n\p1
public class Utility { CD4@0Z+
24\^{3nOK
1! 5VWF0
public Utility() yTf/]H]d
{ uvi&! )x
H(Y1%@
-1w^z`;2h
} )[ejb?{d
TgKSE1
//线程睡眠 5ka6=R(r
public static void sleep(int nSecond) V5gr-^E
{ h;R>|2A
try{ P1|3%#c
Thread.sleep(nSecond); Yy,XKIqU
} (Dn1Eov
catch(Exception e) `#l1
{ m%c]+Our`
e.printStackTrace (); yh'*eli
} ^2i$AM1t
} }|)T<|Y;
2'Raj'2S4
//日志 0a1Mu>P,
public static void log(String sMsg) fS p
{ g"`jWSt7Q
System.err.println(sMsg); 2iC BF-,
} C8=rsh
U&SSc@of
\\{78WDA
public static void log(int sMsg) W,:j>vg
{ <[=[|DS l
System.err.println(sMsg); *%%n9T
} s~k62
} iF_u/#
ygd*zy9
65tsJ"a<
/* -VP_Aw$
**TestMethod.java *2/6fhI[p
*/ Z7 ++c<|p
package NetFox; h7S; 4]
8E>2 6@.
s"~,Zzy@j
public class TestMethod { "#pN
:Ye~I;"8
#v4^,$k>
public TestMethod() 4-9cp=\PE
{ ///xx/weblogic60b2_win.exe d <zD@ z
try{ Kr`.q:0GK
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); fT=ZiHJ3Gu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U^-RyE!}
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y 2^y73&k
fileFetch.start(); mXu";?2
} (1'sBm7F
catch(Exception e){e.printStackTrace ();} gL1r"&^L
Ko "JH=<
S)"vyGv
} $H6ngL
[TT:^F(Y
@;[.#hK
public static void main(String[] args) WK.,q>#
{ \_+Af`
new TestMethod(); fUJe{C<H
} Mi`t$hmP
} Ae<;b Of
点击下载更多相关资料