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)); i27KuPjC
} /@feY?glc
for(int i=0;i<nEndPos.length-1;i++) &)GlLpaT
{ P)rz%,VF+
nEndPos = nStartPos[i+1]; _t.Ub:
} M~LYq
nEndPos[nEndPos.length-1] = nFileLength; (c|Ry[$|
} =L9;8THY
} Wj"GS!5
wLOS,=
' T%70)CM~
//启动子线程 Ot([5/K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $i;_yTht
for(int i=0;i<nStartPos.length;i++) x A"V!8C
{ )Oix$B!-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <= Aqi91
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), LAO2Py#
nStartPos,nEndPos,i); GjeRp|_Qd<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VK3e(7b
fileSplitterFetch.start(); 3U&rK)F
} Bl*.N9*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZP;WXB`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t^SND{[WcM
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gQ=l\/H
nEndPos = " + nFileLength); `~+[pY1r
// fileSplitterFetch[nPos.length-1].start(); ]5sU =\
]o2 Z14
W $EAo+V
//等待子线程结束 yR4++yk
//int count = 0; _a-At
//是否结束while循环 6'6,ySo]
boolean breakWhile = false; t# <(Q
.qg 2zE$0
?i5=sK\
while(!bStop) D,&o=EU
{ Zg/ ],/`
write_nPos(); z%44@TP
Utility.sleep(500); Dio9'&DtC
breakWhile = true; X}G3>HcP
,<O|Iis
K~Z$NS^W&
for(int i=0;i<nStartPos.length;i++) ;b;Bl:%?
{ Zil<*(kv{
if(!fileSplitterFetch.bDownOver) X-}]?OOs
{ @D7/u88|
breakWhile = false; :<i<\TH'
break; }-2U,Xg[
} [s&0O<Wv
} Ah Rvyj
if(breakWhile) >@?`n}r|
break; B'!I{LC
gib'f@i;
\3 M%vJ
//count++; /{FSG!
//if(count>4) 35Cm>X
// siteStop(); Be~In~~
} JHCXUT-r{
dz=pL$C
meArS*d
System.err.println("文件下载结束！"); ;Wedj\Kkp
} erdA?
catch(Exception e){e.printStackTrace ();} #v}pn2g%>
} +5qY*$dn
,B,:$G<
vG#,J&aW
//获得文件长度 v#b(0G
public long getFileSize() JE ''Th}
{ E4qQ
int nFileLength = -1; b3l~wp6>
try{ 8;5@5Au
URL url = new URL(siteInfoBean.getSSiteURL()); 'A)9h7k}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LQXMGgp
httpConnection.setRequestProperty("User-Agent","NetFox"); yL"UBe}v
+!eh\.u|]
;kR+jC(
int responseCode=httpConnection.getResponseCode(); U_<k*o@:
if(responseCode>=400) y?ypRCgO.u
{ HA]5:ck
processErrorCode(responseCode); T/iZ"\(~w
return -2; //-2 represent access is error )kvrQ6
} |ohCA&k%;
v9XevLs
=} flmUv~
String sHeader; E?cf#;2h8m
]3I@5}5%
m)e~HP7M
for(int i=1;;i++) rB}2F*eT
{ ^C70b)68
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mae@L
//Utility.log(in.readLine()); \.Z /
sHeader=httpConnection.getHeaderFieldKey(i); n7(/ml+Q_
if(sHeader!=null) ?#Y1E~N
{ "mB /"
if(sHeader.equals("Content-Length")) K-4o_:F
{ J>Bc-%.Q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *IIuGtS
break; (Ky$(Ubb#6
} .'zcD^
} `[F[0fY-
else *Z2#U?_
break; +XpQ9Cd
} !MEA@^$#
} cg_j.=M-
catch(IOException e){e.printStackTrace ();} rHJtNN8$k
catch(Exception e){e.printStackTrace ();} (Z?g^kjq)
Dgm"1+
(gjCm0#_%
Utility.log(nFileLength); b0uWUI(=
uy8mhB+]
!m6=Us
return nFileLength; s(cC;
} m*'87a9q0
g4}K6)@
)}i|)^J
//保存下载信息（文件指针位置） Dn@Sjsj>
private void write_nPos() _`+2e-
{ A75z/O{
try{ a}V<CBi
output = new DataOutputStream(new FileOutputStream(tmpFile)); x/uC)xm
output.writeInt(nStartPos.length); OpLUmn
for(int i=0;i<nStartPos.length;i++) ,nSapmg
{ yt#~n_
// output.writeLong(nPos); /PZxF
output.writeLong(fileSplitterFetch.nStartPos); Y;#H0v>E
output.writeLong(fileSplitterFetch.nEndPos); BoP,MpF
} I\Pw`
output.close(); rFhi:uRV
} Cp^`-=r+
catch(IOException e){e.printStackTrace ();} #r'S@:[
catch(Exception e){e.printStackTrace ();} 2k+u_tj>
} j W/*-:
A@)ou0[n@
];*?`}#
//读取保存的下载信息（文件指针位置） W4$F\y
private void read_nPos() A9o"L.o)
{ ub]"b[j\1
try{ 5v"Sv
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2 sK\.yS
int nCount = input.readInt(); <8BNqbX
nStartPos = new long[nCount]; %:yVjb,Yf
nEndPos = new long[nCount]; CtE <9?
for(int i=0;i<nStartPos.length;i++) J7p?9
{ Vw+RRi(
nStartPos = input.readLong(); X][=(l!;w7
nEndPos = input.readLong(); fF.sT7Az+
} !NTt'4/F{
input.close(); PE<(eIr
} RSBk^
catch(IOException e){e.printStackTrace ();} zszx~LSvIT
catch(Exception e){e.printStackTrace ();} h~s h!W8
} S)x5.vo^
7.bPPr&
[WO>}rGw4
private void processErrorCode(int nErrorCode) ')>D*e
{ V=)' CCi{
System.err.println("Error Code : " + nErrorCode); /A93mY[
} &VTO9d
Ue(\-b\)
#Q$+AdY|
//停止文件下载 rT';7>{g
public void siteStop() {ZKXT8'
{ 8K2=WYN
bStop = true; Le*gdoW.
for(int i=0;i<nStartPos.length;i++) &;[e
fileSplitterFetch.splitterStop(); PGhYkj2
"=!sZO?3
b=XHE1^rM
} qz8Jvgu?
} W~Q;R:y
//负责部分文件的抓取 fr<V])
**FileSplitterFetch.java RLbo
*/ ^1;Eq>u
package NetFox; A$-\Er+f
e`zCz`R
,D2nUk
import java.io.*; U U@
import java.net.*; b)7v-1N
UnOcw
K[l5=)G0L
public class FileSplitterFetch extends Thread { 3M5wF6nY[[
I}u&iV`
Y'76!Y
String sURL; //File URL `_!R;f
long nStartPos; //File Snippet Start Position oW3|b2D
long nEndPos; //File Snippet End Position m-lTXA(
int nThreadID; //Thread's ID DVjwY_nG7
boolean bDownOver = false; //Downing is over 1@xdzKua1
boolean bStop = false; //Stop identical zo:NE00
FileAccessI fileAccessI = null; //File Access interface k1~? }+<e
="de+S8W
F[*/D/y(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S#nW )=
{ B!((N{4H+
this.sURL = sURL; 6rMNp"!
this.nStartPos = nStart; o8fY!C)
this.nEndPos = nEnd; - *v)sP"@
nThreadID = id; q,>4#J[2;s
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9*2^2GR^;
} @k)[p+)E
@@H?w7y?&
,&G!9}EC
public void run() ]|_+lik#
{ 96i#
while(nStartPos < nEndPos && !bStop) dz1kQzOU*
{ ))4RgS$
1t}
5IfC8drAs
try{ zoZ10?ojC
URL url = new URL(sURL); UdcrX`^.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gl 27&'?E*
httpConnection.setRequestProperty("User-Agent","NetFox"); -l?\hmDl
String sProperty = "bytes="+nStartPos+"-"; $8`"
httpConnection.setRequestProperty("RANGE",sProperty); J$i.^|hE/
Utility.log(sProperty); GezMqt;2
^/~C\ (
;),vUu,k
InputStream input = httpConnection.getInputStream(); GQDW}b8
//logResponseHead(httpConnection); A+hA'0isF@
d fSj= 4
1u~a*lO}
byte[] b = new byte[1024]; 5em*9Ko
int nRead; j7~Rw"(XQc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e?+&2zMq
{ ~W-5-Nl{s
nStartPos += fileAccessI.write(b,0,nRead); 5 Q/yPQN
//if(nThreadID == 1) %Ot*k%F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }J $\<ZT
} BT"n;L?[
]Rj?OSok
\k5 sdHmI[
Utility.log("Thread " + nThreadID + " is over!"); C(kL=WD
bDownOver = true; EkoT U#w5
//nPos = fileAccessI.write (b,0,nRead); GOD{?#c$
} [F 24xC+
catch(Exception e){e.printStackTrace ();} g0#w 4rGF)
} Q^):tO]!Ma
} MH|R@g
* 'Bu-1{
i&j]FX6q
//打印回应的头信息 =k5O*ql"
public void logResponseHead(HttpURLConnection con) lYS*{i1^ '
{ sQn@:Gk
for(int i=1;;i++) =3dd1n;8>
{ ANTWWs}
String header=con.getHeaderFieldKey(i); 7m8(8$-6
if(header!=null) eVj7%9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6eb~Z6n&?
Utility.log(header+" : "+con.getHeaderField(header)); fJ&\Z9zY
else CW -[c
break; F<DXPToX%
} O]KQ]zN
} _gw paAJ
Qh+zs^-?
vbfQy2q
public void splitterStop() Z1{>"o:@
{ o{3>n"\w3
bStop = true; 0wt4C% .0
} a|z@5r%
mDO! o
'xGTaKlm,
} .R)uk
51;[R8'w
~SS3gLv
/* *Tr9pq%m
**FileAccess.java B+MnT{
*//文件访问(定位，写) KxDp+]N]
package NetFox; AWd,qldv
import java.io.*; Cv[1HO<
nPk&/H%5hn
d>V#?1$h
public class FileAccessI implements Serializable{ F?t;bV
3Hi8=*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6FY.kN\
RandomAccessFile oSavedFile; lIPz"
long nPos; ^U##9KkP
LCW}1H:Q
;,s9jw
public FileAccessI() throws IOException hii#kB2
{ C7K]c4T
this("",0); Mbn;~tY>
} -q\Rbb5M
g.\%jDM
ij1YV2v
public FileAccessI(String sName,long nPos) throws IOException N_/+B]r }T
{ {nw.bKq7
oSavedFile = new RandomAccessFile(sName,"rw"); W}#n.c4+
this.nPos = nPos; wF3 MzN=%
oSavedFile.seek(nPos); r"|.`$:B
} C[5dhFZ
^PUB~P/
_fSBb<
public synchronized int write(byte[] b,int nStart,int nLen) ]r'D
{ (T%Ue2zlY
int n = -1; h/6^>setz
try{ + )[@
oSavedFile.write(b,nStart,nLen); GWv i
n = nLen; vM50H
} [LO=k|&R
catch(IOException e) %m+7$iD
{ Vcnc=ct
e.printStackTrace (); PkLNIp1
} i[:cG
#\_8y`{x
]LEaoOecu
return n; z#1"0Ks&P
} 20}w.V
sPXjU5uq#
UZ#oaD8H6
} Vf<q-3q
;e< TEs
%NM={X|'
/* M&)\PbMc
**SiteInfoBean.java _EJPI
*/ 3_`)QYU'
package NetFox; \0vs93>?
!qU1RdZ
N9*:]a
public class SiteInfoBean { uP(t+}dQ+3
IUNr<w<
t#3_M=L
private String sSiteURL; //Site's URL |* ^LsuFb
private String sFilePath; //Saved File's Path [A~ Hl
private String sFileName; //Saved File's Name dMCoN8W
private int nSplitter; //Count of Splited Downloading File 6P:fM Y
0a bQY
t=9f:,I$
public SiteInfoBean() jsx&h Y%(
{//nSplitter的缺省值为5 {&UA60~6
//default value of nSplitter is 5 57=d;Yg e
this("","","",5); K:GEC-
} WIuYSt)h
g[bu9i
:Zx|=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v5@M 34
{ s;Gg
sSiteURL= sURL; )(_NFpM
sFilePath = sPath; A=IpP}7J
sFileName = sName; esj6=Gh
this.nSplitter = nSpiltter; 2pU'&8
DR,7rT{$
dfKGO$}V
} Ow.DBL)x'>
r/HTkXs I
5+;Mc[V3-
public String getSSiteURL() IvlfX`("
{ jM @N<k
return sSiteURL; 0{ ~2mggh
} C ocw%Yl
VBw5[
t 7o4 aBl"
public void setSSiteURL(String value) ZO/u3&gU
{ W]bgWKd
sSiteURL = value; x)GheM^
} GM?s8yZ<
aKWxLe
^g5E&0a`g
public String getSFilePath() 0zkMRBe
{ {u2Zl7]z^
return sFilePath; EmR82^_:
} C=]<R<Xy
MkL2I+*
_> x}MW+
public void setSFilePath(String value) 0y+^{@lU
{ @!u{>!~0
sFilePath = value; +L`}(yLJ)9
} I:G8B5{J
{-8Nq`w
'Grii,
public String getSFileName() ge:a{L
{ &)gc{(4$
return sFileName; =y_KL
} )GAlj;9A$
xr7}@rq"U<
Dmr*Lh~
public void setSFileName(String value) y_}vVHT,
{ 1[8^JVC>6
sFileName = value; i?;#ZNh
} s)`(@"{
bxtH`^
Qrg- xu=
public int getNSplitter() At?|[%<`
{ Q?1J<(oq9
return nSplitter; {59>U~
} 4=/jh:h
XsQ81j.
1n +Uv*
public void setNSplitter(int nCount) Tx!t3;Yz[
{ A|S)cr8z
nSplitter = nCount; 6p*X8j3pW
} rDhQ3iCqo
} ?]$<Ufr
Qn.dL@W
&1yJrj9y
/* 0NGth(2
**Utility.java z k/`Uz
*/ 6PYt>r&TO
package NetFox; cWZITT{A
tWTHyL
#~)A#~4O
public class Utility { _.Hj:nFHz
`;+x\0@<
*X/Vt$P
public Utility() G3io!XM)D
{ /MY's&D(
vj%"x/TP
{$hWz(
} nPdkvs
i.uyfV&F
//线程睡眠 -dA9x~o
public static void sleep(int nSecond) R/Bjc}J'
{ $cHU,
try{ kY\faWuR
Thread.sleep(nSecond); DxNob-Fr
} 2Ax"X12{6
catch(Exception e) Rw{' O]Q*
{ z+7V}aPM
e.printStackTrace (); bE.<vF&
} 4@3\Ihv
} *3`R W<Z
H'zAMGZa
//日志 #p>&|I
public static void log(String sMsg) :?\29j#*V
{ iYgVSVNg
System.err.println(sMsg); RU7+$Z0K
} q"<=^vi
`e<IO_cg
9dNkKMc@
public static void log(int sMsg) SoM,o]s#y
{ JxtzI2
System.err.println(sMsg); <q$Tk,
} 7HH@7vpJ^
} }6\,kFc
?V8Fgd
XXum2eA
/* 4"kc(J`c
**TestMethod.java mc%. 8i
*/ nUpj+F#
package NetFox; Q4-d|
e}yF2|0FD
(0q`eO2
public class TestMethod { z2YYxJc&w
!~9ASpqvPy
O=7S=Rm4&
public TestMethod() 3WF]%P%
{ ///xx/weblogic60b2_win.exe n'^`;-
try{ |.$B,cEd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yKl^-%Uq<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); H!]&"V77
SiteFileFetch fileFetch = new SiteFileFetch(bean); -%MXt
fileFetch.start(); S8dfe~|7:
} !7I07~&1
catch(Exception e){e.printStackTrace ();} "[~yu* S
]sb?lAxh{
36(qe"s
} &?bsBqpN
_]o7iqtv
X,l7>>L{g
public static void main(String[] args) ,4xNW:!j
{ 2[`n<R\
new TestMethod(); DSRc4|L
} |e@1@q(a[]
} $7Hwu^c(
点击下载更多相关资料