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)); Ix+===6
} Y^zL}@
for(int i=0;i<nEndPos.length-1;i++) Gk'j<a
{ <SiD m-=E
nEndPos = nStartPos[i+1]; 7@[3]c<=
} bjgf8427I
nEndPos[nEndPos.length-1] = nFileLength; 4nC`DJ;V
} KfC8~{O-
} xM ]IU <
4vri=P 2%
.C]V==z`[4
//启动子线程 ^P5+ _P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; jy=dB-&
for(int i=0;i<nStartPos.length;i++) ]1A"l!yf
{ 'b#`)w@/=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6`sOhVD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K<@gU\-!
nStartPos,nEndPos,i); #St=%!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;aZ$qgN*Y
fileSplitterFetch.start(); ,@+7(W
} MQL1/>j;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,2Y PD4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fz%I'+!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E)eRi"a46
nEndPos = " + nFileLength); '4gi*8Y
// fileSplitterFetch[nPos.length-1].start(); rlj @'
;]ojfR=?%
"=cWcztiP
//等待子线程结束 SU0K#:
//int count = 0; LnQm2uF
//是否结束while循环 "CYh"4]@rD
boolean breakWhile = false; ldjypEa}
T[mo PD5
!PN;XZ~{
while(!bStop) nC^|83
{ V^O dTM
write_nPos(); owClnp9K
Utility.sleep(500); _dCsYI%
breakWhile = true; (kpn"]^'
zYf`o0U
y`"b%P)+T
for(int i=0;i<nStartPos.length;i++) m'Jk!eo
{ C$X )I~M
if(!fileSplitterFetch.bDownOver) +\SNaq~&
{ OiB*,TWV
breakWhile = false; %9z N U
break; |meo
} &3x \wH/_
} E?c)WA2iH
if(breakWhile) wGd4:W
break; V K/;ohTTP
W~15[r0
D-)jmz>R
//count++; Lod$&k@@
//if(count>4) TH_Vw,)
// siteStop(); 9N(<OY+Dgm
} Dq/ _#&S
%B^nQbNDM
<VP@#
System.err.println("文件下载结束！"); I!(.tu6u6c
} #q{i<E 07
catch(Exception e){e.printStackTrace ();} Dp:u!tdbeg
} P0m;AqS#R
]h0Fv-[A
b6Jv|1w'
//获得文件长度 z/bJDSQ
public long getFileSize() #(o 'G4T
{ !!Tk'=t9"3
int nFileLength = -1; 0 S3~IeJ
try{ Ndj9B|s_
URL url = new URL(siteInfoBean.getSSiteURL()); 7g(,$5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;6N@raP7
httpConnection.setRequestProperty("User-Agent","NetFox"); ?!H<V@a
\tc`Aj%K
&FrW(>2
int responseCode=httpConnection.getResponseCode(); ;IhkGPpWP
if(responseCode>=400) Fs q=u-= :
{ *G"vV>OSV
processErrorCode(responseCode); tAD{{GW9
return -2; //-2 represent access is error hJ8|KPgdw
} Vq`i.>%5
"65@8xt==
MpbH!2J
String sHeader; .pNPC|XU
`Q2 `":
6l|pTyb1
for(int i=1;;i++) S[fzy$">
{ ]A}'jP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vt`hY4
//Utility.log(in.readLine()); -#]?3*NO
sHeader=httpConnection.getHeaderFieldKey(i); jEBZ"Jvb
if(sHeader!=null) o[AQS`
{ 1gp3A
if(sHeader.equals("Content-Length")) C3fSSa%b
{ ${n=1-SMU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xZ2}1D
break; [3`T/Wm
} {Y{*(5YV
} Ya] qo]
else b&uo^G,
break; <Sn5ME<*
} azMrY<
} }G$rr.G
catch(IOException e){e.printStackTrace ();} zGFo-C
catch(Exception e){e.printStackTrace ();} }a@ZFk_>
[V`j@dV
9OB[ig
Utility.log(nFileLength); 2#Fc4RR;
Ij>x3L\-
>j1\]uo
return nFileLength; jRXpEiM
} y4`<$gL
>So)KB
Ww*='lz
//保存下载信息（文件指针位置） j3QpY9A
private void write_nPos() ocwRU0+j
{ R4,j
try{ h'wOslyFa
output = new DataOutputStream(new FileOutputStream(tmpFile)); YIA}F1:
output.writeInt(nStartPos.length); wC@5[e$
for(int i=0;i<nStartPos.length;i++) 2Mx9Kd'a r
{ +r)'?zU
// output.writeLong(nPos); W(9fCDO;
output.writeLong(fileSplitterFetch.nStartPos); ToIvyeFr
output.writeLong(fileSplitterFetch.nEndPos); a pqzf
} $3](6
output.close(); ?4=8z8((!
} D%cWw0Oq
catch(IOException e){e.printStackTrace ();} ouKID_'
catch(Exception e){e.printStackTrace ();} HxJKS*H;
} +~J?/
d,au&WZ;_
c_xtwdkL9
//读取保存的下载信息（文件指针位置） =?UCtYN,P
private void read_nPos() FKflN
{ yn<z!z%mz
try{ H<|I&nV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eW)(u$C|qL
int nCount = input.readInt(); iZ+\vO?|
nStartPos = new long[nCount]; "|pNS)
nEndPos = new long[nCount]; UM%[UyYQ
for(int i=0;i<nStartPos.length;i++) cOra`7L`
{ a#W:SgE?Y
nStartPos = input.readLong(); wL,b.]
nEndPos = input.readLong(); }*l V
} ~I6Er6$C^
input.close(); ,YFuMek
} NUBzmnA>8
catch(IOException e){e.printStackTrace ();} 0`/PEK{
catch(Exception e){e.printStackTrace ();} vrXmzq
} D1bS=> ;,"
#V[?puE@
U:>'^tkp
private void processErrorCode(int nErrorCode) b3e:F{n ^
{ pmXx2T#=
System.err.println("Error Code : " + nErrorCode); wzB*M}3
} S4kGy}{+i
RsU=fe,
$DW3H1iW
//停止文件下载 fXMVl\ <
public void siteStop() QOIi/flK
{ 9@C3jZ+9`H
bStop = true; o9M[Zr1@k
for(int i=0;i<nStartPos.length;i++) ''!pvxA
fileSplitterFetch.splitterStop(); VP=(",`
48M)A
xI'<4lo7Z
} \/4ipU.
} w\=zTHo88
//负责部分文件的抓取 ;nG"y:qq
**FileSplitterFetch.java ]@1YgV
*/ XhFa9RC
package NetFox; ke|v|@
94%gg0azp
j~V@0z.
import java.io.*; w.J[3m/
import java.net.*; e;pVoRI
hu\HK81m
bJe*J\){
public class FileSplitterFetch extends Thread { ~c[}%Ir>
_Jj/"?
qie7iE`o
String sURL; //File URL YE&"IH]lF
long nStartPos; //File Snippet Start Position 8 f%@:}H
long nEndPos; //File Snippet End Position ` 1DJwe2
int nThreadID; //Thread's ID 2;%DE<Z
boolean bDownOver = false; //Downing is over )F&@ M;2p'
boolean bStop = false; //Stop identical =If% m9
FileAccessI fileAccessI = null; //File Access interface C1P{4 U
{rGq|Bj
Vn? %w~0!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I"@X~Y7}
{ y|q4d(P.
this.sURL = sURL; d9|dHJf
this.nStartPos = nStart; #/@U|g
this.nEndPos = nEnd; gBHev1^y
nThreadID = id; xBU\$ToC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;OmmXygl
} X`]-)(UX
:w(J=0Lt
mp0p#8txi
public void run() +] B
{ sW+YfJT
while(nStartPos < nEndPos && !bStop) %Rr!I:[ $
{ ?AP2Opsl
TW).j6@f
%@$h?HP
try{ q#v.-013r
URL url = new URL(sURL); QRdNi1&M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $ZYEH
httpConnection.setRequestProperty("User-Agent","NetFox"); %0INtq
String sProperty = "bytes="+nStartPos+"-"; o^4qY
httpConnection.setRequestProperty("RANGE",sProperty); <1&kCfE&
Utility.log(sProperty); ~X5yHf3
+,7dj:0S
c a_N76o!
InputStream input = httpConnection.getInputStream(); [e3|yE6
//logResponseHead(httpConnection); -'JTVfm.
;|w &n
z=!$3E ecr
byte[] b = new byte[1024]; [6 wI22
int nRead; [V{JuG;s
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) KoiU\r
{ 64s+ 0}
nStartPos += fileAccessI.write(b,0,nRead); B P"PUl:
//if(nThreadID == 1) %H>vMR-,~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |`s}PcV
} 66D<Up'K
wc)[r~On(5
*x`z5_yfO
Utility.log("Thread " + nThreadID + " is over!"); FFbMG:>:
bDownOver = true; 4DEsB)%X
//nPos = fileAccessI.write (b,0,nRead); cGkl=-oQ'
} R%aH{UhE`
catch(Exception e){e.printStackTrace ();} b@^M|h.Va
} L;nRI.
} 52m^jT Sx
?Li^XONz
a%tm[Re
//打印回应的头信息 `NXyzT`:K
public void logResponseHead(HttpURLConnection con) dpZ7eJ
{ sxgR;gf6
for(int i=1;;i++) _XXK1H x
{ 7EY~5U/4
String header=con.getHeaderFieldKey(i); \bQ|O7s
if(header!=null) IG`~^-}7lR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2P$lXGjh
Utility.log(header+" : "+con.getHeaderField(header)); jCW>=1:JGY
else (&PamsV*8
break; 'nP'MA9b;a
} ^K@r!)We
} 6\ux;lksn*
vc6UA%/f
tt[P{mMQ
public void splitterStop() 98Srn63O
{ ="@W)"r
bStop = true; HCHP15otfe
} Qu!\Cx@
<tf4j3lwH
R|V<2
} G&D N'bp
E=~H,~
dtA- 4Ndm
/* ^Q!:0D*
**FileAccess.java +n,8o:fU:
*//文件访问(定位，写) ~Zl`Ap
package NetFox; ;zs*Zd7h M
import java.io.*; )@eBe^
|r}%AN6+
+D?d)lK
public class FileAccessI implements Serializable{ UgJlXB|a%2
~(aq3ngo.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Zt lS*id_
RandomAccessFile oSavedFile; ]|u}P2
long nPos; "oz@w'rG
7;CeQx/W)W
[2i+f<
public FileAccessI() throws IOException `Z|sp
{ =#BeAsFfO
this("",0); rO]C`bg
} 1Dt"Rcn"4
yp@mxI@1
$k'f)E
public FileAccessI(String sName,long nPos) throws IOException 3Xd+>'H
{ NnHwk)'
oSavedFile = new RandomAccessFile(sName,"rw"); V]q{N-Iq
this.nPos = nPos; d.2b7q09
oSavedFile.seek(nPos); )V@qH]
} }S#.Pw%
`}zv17wp
Jk{>*jYk`
public synchronized int write(byte[] b,int nStart,int nLen) w-B\AK?}
{ Lj~lfO
int n = -1; .&sguAyG
try{ E*(Q'p9C
oSavedFile.write(b,nStart,nLen); Efp=z=E
n = nLen; @lTUag'U0
} UBqK$2 #
catch(IOException e) GC4$9q}C4Z
{ JYSw!!eC
e.printStackTrace (); FblGFm"P
} :[ITjkhde0
n|,Es!8:o
XX6&%7(
return n; #m$H'O[WG\
} xje{kx#
yLDHJ}R
,7j`5iq[m
} ;euWpE;E\#
a@8knJ|
..~{cU4Tt
/* z? {#/
**SiteInfoBean.java qWanr7n]@
*/ ?5(L.XFm
package NetFox; Fn[~5/
qb"!
QlXy9-oJ"
public class SiteInfoBean { Rp@u.C<
htF&VeIte
(vI7qD_
private String sSiteURL; //Site's URL Ce0I8B2y
private String sFilePath; //Saved File's Path wz, \zh
private String sFileName; //Saved File's Name wR;l"*j
private int nSplitter; //Count of Splited Downloading File N$y4>g
>#q|Pjv]
~(Tz <
public SiteInfoBean() M}nalr+#
{//nSplitter的缺省值为5 BMdr.0
//default value of nSplitter is 5 NGze: gPmO
this("","","",5); +$UfP(XmH
} JHQ8o5bEQp
@?1%*/
[=9R5.)c
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .Z^g 7 *s
{ B}MJ?uvA
sSiteURL= sURL; sRMzU
sFilePath = sPath; |SxEJ
sFileName = sName; w(G(Q>GI
this.nSplitter = nSpiltter; ALwuw^+
9V"j=1B}
K&X'^|en
} )T4L^^`
`773& \PK
Qb|dp~K.M
public String getSSiteURL() G{"1I
{ 0)/214^&
return sSiteURL; )8<X6
} c8'8DM
I#Bz UF
Ym6ec|9;
public void setSSiteURL(String value) (8*lLZ
{ `j(+Y
sSiteURL = value; T2->
} $?s^HKF~
s{IoL_PJP
_4W#6!
public String getSFilePath() srSTQ\l4
{ T9$U./69-L
return sFilePath; kDz.{Ih
} UP`q6]P
"/"qg
$e_ps~{7$
public void setSFilePath(String value) E??%)q
{ C=]3NB>Jc
sFilePath = value; OP&[5X+Y
} D!P?sq_5r
XMdc n,
wiGwN
public String getSFileName() ]lo1Kw
{ |HA7 C
return sFileName; KF'M4P
} Qnw$=L:
J)G3Kq5>:b
y8 Nb8m
public void setSFileName(String value) HUghl2L.<
{ l<HRD
sFileName = value; C:K\-P9
} N:<O
Y]lqtre*Y
$"i690
public int getNSplitter() vqs~a7E-P
{ ,,J3 h
return nSplitter; C1/jA>XW
} ;FmSL#]I
wY95|QS
d"78:+
public void setNSplitter(int nCount) y(dS1.5F
{ +doT^&2u*
nSplitter = nCount; br;G5^j3?
} ]M2<I#hF.
} ]/bE${W*]
i#lo?\PO>
ypd?mw&1}
/* ]R@G5d
**Utility.java 2tv40(M:<
*/ `#f=&S?k
package NetFox; caP
-1:Z^&e/
.#@Dn(
public class Utility { m\f_u*
(2li:1j
nADd,|xD3
public Utility() /ZDc=>)~
{ 5\S7Va;W
SoX V
mig3.is
} X W)A~wPBs
Ic}ofBK
//线程睡眠 ~Hs{(7
public static void sleep(int nSecond) !_) ^bRd
{ _p&$X
try{ ;N\?]{ L
Thread.sleep(nSecond); S:YL<_oI|
} j 7URg>i0
catch(Exception e) nrIL_
{ !cb#fl
e.printStackTrace (); ?nW#qy!R
} bY~v0kg
} YZl%JX
IFxI>6<&
//日志 "^z=r]<5
public static void log(String sMsg) 8Y{s;U0n
{ |b.z*G
System.err.println(sMsg); u, kU$
} wk$,k
(! KG)!
;ojiJ?jU
public static void log(int sMsg) sYn[uPefj
{ Vxdp|
System.err.println(sMsg); lU.Kc
} rAukHeH
} j]5WK_~M
SvuTc!$?
63&^BW
/* HlB]38
**TestMethod.java MXZ>"G
*/ uA~slS Z
package NetFox; B3 zk(RNZ
:1aL ?
@WOM#Kc
public class TestMethod { vq'k|_Qi=
?Rr2/W#F
Fx#jV\''s
public TestMethod() p*qPcuAA
{ ///xx/weblogic60b2_win.exe SW 8x]B
try{ P3o@gkXP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {"}V&X160o
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -Zc![cAlO
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q!'qC*Gyfn
fileFetch.start(); Ew,T5GG
} fZN><3MO>
catch(Exception e){e.printStackTrace ();} uzU{z;
Z"v<0]rN
C/@LZ OEL
} I.jZ wW!r
8l+H"M&|
k*Nr!Z!}
public static void main(String[] args) raUs%Y3
{ jAhP> t:
new TestMethod(); B6M+mx"G
} SoQR#(73HK
} (K{5fC
点击下载更多相关资料