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)); ,c"_X8Fkx$
} QytqO{B^
for(int i=0;i<nEndPos.length-1;i++) 2%0zPflT
{ x8%Q TTY
nEndPos = nStartPos[i+1]; }xTTz,Oj$
} |33pf7o
nEndPos[nEndPos.length-1] = nFileLength; j>~^jz:
} uy\<t
} T/G1v;]
P\;lH"9
B&A4-w v
//启动子线程 [dFxW6n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; XOzPi*V**
for(int i=0;i<nStartPos.length;i++) P8!Vcy938
{ CYrVP%xRA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r AMnM>`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jPYed@[+
nStartPos,nEndPos,i); zR h1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fV*x2g7w
fileSplitterFetch.start(); Ous[{"-J
} W>eJGZ<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W"4E0!r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {EbR =
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", STu!v5XY}-
nEndPos = " + nFileLength); g[Ah> 5
// fileSplitterFetch[nPos.length-1].start(); 'qQ 5K o
fI[tU(x
YIb5jK`
//等待子线程结束 *%(8z~(\
//int count = 0; v=nq P{
//是否结束while循环 ,GXwi|Y
boolean breakWhile = false; &H,5f#
qa#Fa)g*
@B5@3zYs
while(!bStop) [P8Y
{ OQaM47"
write_nPos(); c#nFm&}dm
Utility.sleep(500); .:Bjs*
breakWhile = true; wl2rw93
6~?7CK
/S1EQ%_
for(int i=0;i<nStartPos.length;i++) CyO2Z
{ p%,:U8fOR
if(!fileSplitterFetch.bDownOver) 3;~1rw=$<
{ o%X_V!B{V
breakWhile = false; `x$d8(1J`#
break; >x@]wsj
} X!&DKE
} %1SA!1>j
if(breakWhile) aq~hl7MTj
break; 8#'<SB
hXM8`iFW5
~\4l*$3(^
//count++; )v;>6(
//if(count>4) AuUT 'E@E
// siteStop(); w_pEup\`
} m9ts&b+TE
F6h3M~uR
*c7kB}/
System.err.println("文件下载结束！"); %]nYv#K
} @=`Dw/13
catch(Exception e){e.printStackTrace ();} ,0NVb7F;k
} z*ZEw
2\l7=9 ]\3
Z"'rc.>a
//获得文件长度 jVL<7@_*
public long getFileSize() ^"v~hjM#
{ UevbLt1Y
int nFileLength = -1; J|_&3@r
try{ ^M6v;8EU
URL url = new URL(siteInfoBean.getSSiteURL()); im9 B=D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /XS6X
httpConnection.setRequestProperty("User-Agent","NetFox"); '?t]iRCeI7
[J\5DctX;c
9_JK.
int responseCode=httpConnection.getResponseCode(); :Gqyj_|<
if(responseCode>=400) 9=@j]g|
{ >T;"bcb
processErrorCode(responseCode); ]Gow
return -2; //-2 represent access is error *$/7;CLq
} yw"FI!M
j]rE0Og
>4}+\ Q`S
String sHeader; h'^7xDw
2/=CrK
6:>4}WOP
for(int i=1;;i++) ??=CAU%\
{ /ivt8Uiw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]0by6hQ
//Utility.log(in.readLine()); cf1Ve\(YGI
sHeader=httpConnection.getHeaderFieldKey(i); 'Kxs>/y3
if(sHeader!=null) -en:81a#
{ }|H]>U&
if(sHeader.equals("Content-Length")) (`GO@
{ "6^tG[G%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,& =(DJ
break; tf|/_Y2
} #!rng]p
} iHr{ VQ
else VF!?B>
break; |!8[Vg^Wh
} jC ,foqL
} f3lFpS
catch(IOException e){e.printStackTrace ();} <i^Bq=E<rJ
catch(Exception e){e.printStackTrace ();} N\=pH{
?'CIt5n+\{
pA"x4\s
Utility.log(nFileLength); ()JM161
1lfkb1BM
k6ERGQ9|I
return nFileLength; f%ZqK_CW
} [0yKd?e
?(Dkh${@
9H2^4D8
//保存下载信息（文件指针位置） K6@QZc5.!
private void write_nPos() =#^%; 66z
{ D^=_408\
try{ L{bcmo\U
output = new DataOutputStream(new FileOutputStream(tmpFile)); go m<V?$
output.writeInt(nStartPos.length); c?CwxI_b8
for(int i=0;i<nStartPos.length;i++) gZ
{ x%B^hH;W
// output.writeLong(nPos); @Rj&9/\L
output.writeLong(fileSplitterFetch.nStartPos); =DvFY]9{
output.writeLong(fileSplitterFetch.nEndPos); dl'pl
} Me yQ`%
output.close(); vi4u `
} 6/hY[a!
catch(IOException e){e.printStackTrace ();} i&-g 0
catch(Exception e){e.printStackTrace ();} n*CH,fih:
} {#:js
upQ:C>S
PH9MB
//读取保存的下载信息（文件指针位置） qCSJ=T;
private void read_nPos() =`xk|86f
{ iN0pYqY*
try{ ?}m/Q"!1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <?&GBCe
int nCount = input.readInt(); Tc,Bv7:
nStartPos = new long[nCount]; ;i^p6b j
nEndPos = new long[nCount]; UAnq|NJO
for(int i=0;i<nStartPos.length;i++) jiYYDGs77
{ h/5n+*x(
nStartPos = input.readLong(); Fo3[KW)8I
nEndPos = input.readLong(); 8;P8CKe
} 'M|W nR
input.close(); \2U^y4K.
} Sh=E.!
catch(IOException e){e.printStackTrace ();} <>A:Oi3^
catch(Exception e){e.printStackTrace ();} a k@0M[d
} @j`_)Y\
g[@Kd
2JYp.CJv
private void processErrorCode(int nErrorCode) gTY\B.
{ mwZesSxB_
System.err.println("Error Code : " + nErrorCode); yrnB]$hf
} pAtHU(}
8;4vr@EV
Pqo_+fL+
//停止文件下载 S+R<wv,6
public void siteStop() >"f,'S5*
{ BXO(B'1)]
bStop = true; VE& ?Zd~
for(int i=0;i<nStartPos.length;i++) Oq(_I b)9
fileSplitterFetch.splitterStop(); /4YXx|V
PYkcGtVa_
k[6@\D-
} }el.qZ
} e7t).s)b{
//负责部分文件的抓取 +[UFf3(ON
**FileSplitterFetch.java wA+J49
*/ ^uW](2
package NetFox; _YWw7q
yX,2`&c
l\-1W2
import java.io.*; HLg/=VF7?
import java.net.*; 1Z'cL~9
9hHQWv7TgK
FviLlly6
public class FileSplitterFetch extends Thread { -TU7GCb=
}IC$Du#
r[vMiVb
String sURL; //File URL A-~#ydv
long nStartPos; //File Snippet Start Position :&mYz(1q
long nEndPos; //File Snippet End Position iJ~5A'?6
int nThreadID; //Thread's ID [3nhf<O
boolean bDownOver = false; //Downing is over S5@/;T
boolean bStop = false; //Stop identical fa=#S
FileAccessI fileAccessI = null; //File Access interface SDcxro|8i
p.n]y=o.)
F:%= u =
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j2cLb
{ K7FuMB
this.sURL = sURL; },2-\-1
this.nStartPos = nStart; DIB Az s
this.nEndPos = nEnd; W8,XSUl
nThreadID = id; hmtRs]7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @/lLLGrZ"
} W,`u5gbT
f~jx2?W
u6'vzLmM
public void run() #^gn,^QQ
{ {:IOTy
while(nStartPos < nEndPos && !bStop) l,1}1{k&
{ 9r fR
j?jEWreq]~
?g}n$%*5y!
try{ >MUwT$szs
URL url = new URL(sURL); ::uD%a zd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /R8>f
httpConnection.setRequestProperty("User-Agent","NetFox"); XLwbA4ORq
String sProperty = "bytes="+nStartPos+"-"; ];R5[%:5
httpConnection.setRequestProperty("RANGE",sProperty); u'd+:uH
Utility.log(sProperty); f62z9)`^
W:aAe%S
LbJtU!
InputStream input = httpConnection.getInputStream(); ~q?IG5s*Z
//logResponseHead(httpConnection); 0Tp?ED_
-3/:Dk`3
_c['_HC
byte[] b = new byte[1024]; }zj w\
int nRead; r6Lb0PzMf
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q`7!~qV0=
{ '/\@Mc4T
nStartPos += fileAccessI.write(b,0,nRead); FZ #ngrT
//if(nThreadID == 1) WVftLIJ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r[eZV"
} k*-_CO-h
D=mU!rjr1
Lbq"( b
Utility.log("Thread " + nThreadID + " is over!"); _0)#-L>xKF
bDownOver = true; X9/V;!
//nPos = fileAccessI.write (b,0,nRead); C(3yJzg>y
} i`gsT[JQRX
catch(Exception e){e.printStackTrace ();} P~#!-9?
} \_!FOUPz(
} E(4ti]'4
S&6}9r
.hg<\-:_
//打印回应的头信息 H #J"'
public void logResponseHead(HttpURLConnection con) :u'X ~ID[
{ DGC-`z
for(int i=1;;i++) ;QR|v
{ prlnK
String header=con.getHeaderFieldKey(i); 5u:+hB
if(header!=null) r4gkSwy
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5dMIv<#T`
Utility.log(header+" : "+con.getHeaderField(header)); %Wom]/&,'
else s2@N&7"u)
break; w(J-[t118
} @!Il!+^3
} [{Fr{La`D'
$.QnM
H+F?)VX}oA
public void splitterStop() T5z %X:VD(
{ BtBo%t&
bStop = true; "ltvD\
} 8q)2)p
`-\4Dx1!q
Z%`} `(
} 7FqmT
9u1_L`+b
CHdw>/5
/* NRcg~Nu
**FileAccess.java mZ/?uPIa
*//文件访问(定位，写) (*/P~$xIj
package NetFox; s$C;31k
import java.io.*; 9$~D4T
{Xwin$C
z Rz#0
public class FileAccessI implements Serializable{ 8!3+Obj
@IB8(TZ5I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "3Dvc7V
RandomAccessFile oSavedFile; VDPqI+z
long nPos; %saTyF,
Fy`VQ\%7t
).9-=P HlX
public FileAccessI() throws IOException ;)83tx /
{ 3Nr8H.u&q
this("",0); k|BY 7C
} Xvi{A]V
56>Zqtp*
,$}P<WZMu
public FileAccessI(String sName,long nPos) throws IOException sG}}a}U1
{ %a5Sc|&-
oSavedFile = new RandomAccessFile(sName,"rw"); G2;Uv/vR
this.nPos = nPos; *B#OLx
oSavedFile.seek(nPos); U^VFHIm
} uji])e MN~
To}L%)
5iG|C ~
public synchronized int write(byte[] b,int nStart,int nLen) k/H<UW?Z]
{ 1ikkm7
int n = -1; ^[&*B#(
try{ 6du"^g
oSavedFile.write(b,nStart,nLen); s_zZ@azJ
n = nLen; Y91TF'
} xtpD/,2
catch(IOException e) j[iJo 5
{ p&Nw:S
e.printStackTrace (); Kl(}s{YFn.
} ]K XknEaxl
0 v/+%%4}
JR 2v}b
return n; A |NX"
} OTN"XKa$
U=Z@Ipu5T
'!yyg#
} b2U[W#
`"GD'Oa
(cC5zv*E
/* nqgfAQsE)
**SiteInfoBean.java w V;y]'
*/ #xYkG5`lm
package NetFox; BzTm[`(h
$T;3*D90
YyK9UZjI
public class SiteInfoBean { aFIet55o
#g~~zwx/N
@{+*ea7M(`
private String sSiteURL; //Site's URL u>k;PUH4
private String sFilePath; //Saved File's Path &_q;X;}
private String sFileName; //Saved File's Name um&N|5lHb
private int nSplitter; //Count of Splited Downloading File 5mER&SX
Rv.W~FE^
(ter+rTv
public SiteInfoBean() O-|RPW}
{//nSplitter的缺省值为5 CdWGb[uI
//default value of nSplitter is 5 qaw5<
this("","","",5); G?3S_3J2
} OX8jCW
Q{>9Dg
p&vQ*}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y,Dfqt
{ N#T MU
sSiteURL= sURL; XKks j!'B
sFilePath = sPath; `+"QhQ4w
sFileName = sName; KO{}+~,.6
this.nSplitter = nSpiltter; Kz$Ijj
~\ie/}zYj
ip1jY!
} bpUN8BI[T
;pAkdX&b
^$?8!WE
public String getSSiteURL() _QXo4z!a8
{ QXXcJc~
return sSiteURL; c^Wm~"r
} FAPgXmFzx
@o;m!CYB
>x!N[N@G
public void setSSiteURL(String value) (&njZdcb*
{ 61jDI^:
sSiteURL = value; 6|_ S|N
} V#3VRh
;`F0 %0d
RL)'m
public String getSFilePath() ?$ YE
{ qIb(uF@l"
return sFilePath; laFkOQI
} ?#FAa,
hrS/3c'<Z
~x4Y57
public void setSFilePath(String value) jg%D G2
{ XZKOBq B]
sFilePath = value; ghms-.:b8
} <<UlFE9"
k{@z87+&
Ch7eUTqA@
public String getSFileName() AiO,zjM=
{ f kP WGd
return sFileName; ~_S`zzcZy4
} [FC%_R&&
YI\^hP#
-p%=36n
public void setSFileName(String value) &TK%igL
{ 1ViDS
sFileName = value; YVs{\1|'
} 1XHGW=n
9oGsrClH
L G=Q
public int getNSplitter() rNgE/=X
{ FEdyh?$
return nSplitter; c)E'',-J_2
} -Tz9J4xU&
ja9y
E)Hp.
public void setNSplitter(int nCount) wHIS}OONz
{ u$a%{46
nSplitter = nCount; 'i`;Frmg
} y<;#*wB
} {ifYr(|p`
l@Ml8+
hob%'Y5%D
/* V}aXS;(r%
**Utility.java wz:wR+
*/ JH?[hb
package NetFox; d}WAP m
re^1fv
0} {QQB
public class Utility { .@[+05Yw
qbT].,?!U
$(_i>&d<
public Utility() c\RDa|B,
{ v$,9l+p/
_N*4 3O`
(# ?~^ut
} sS+9ly{9J
]INbRytvc
//线程睡眠 )IhI~,0Nmj
public static void sleep(int nSecond) Y@L`XNl
{ HPt"
try{ T>1E
Thread.sleep(nSecond); Yoaz|7LS
} KH[%HN5v
catch(Exception e) { >4exyu6
{ $/pd[H[{
e.printStackTrace (); lYJ]W[!
} Y> 7/>x6
} <M 7WWtmx
|'a5nh!
//日志 %tpt+N?
public static void log(String sMsg) O(!wDnhc
{ rb,&i1
System.err.println(sMsg); *8MU,6
} b$M? _<G
]Oe#S"-Oo
B)Gm"bLCOZ
public static void log(int sMsg) XmXHs4
{ y]@_DL#J=
System.err.println(sMsg); 9]d$G$Kv9
} Kk#8r+,
} BWQ (>Z"
*t*yozN
1?mQ fW@G
/* !".@Wg$
**TestMethod.java T}fo:aB}
*/ U?@UIhtM|
package NetFox; qwVpGNc45
;O.U-s
)vo PH)!
public class TestMethod { O5e9vQH
Gn&)*qCO
<0Q`:'\.>
public TestMethod() UT>\u
{ ///xx/weblogic60b2_win.exe \1|T
try{ &@{Ba~S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =f{r+'[;^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 44b'40
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6rPe\'n=B
fileFetch.start(); /FB'
} w~1K93/p!
catch(Exception e){e.printStackTrace ();} LN_6>u
dD!} P$
|\elM[G"g
} wUl}x)xo
9jJ&QACn
DJ=miJI'
public static void main(String[] args) HO$s&}t
{ 191O(H
new TestMethod(); 3hb1^HNT
} k>2 xm
} w^P4_Yr[T
点击下载更多相关资料