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)); sfEy
} { daEKac5
for(int i=0;i<nEndPos.length-1;i++) ]1i1_AR'`
{ XZ1<sm8t."
nEndPos = nStartPos[i+1]; =:7OS>x
} &^b mZj!
nEndPos[nEndPos.length-1] = nFileLength; An3%@;
} c UHKE\F
} 4.i< `'
WH0$v#8`v
.^JsnP
//启动子线程 tCP;IU$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; DTSK*a`
for(int i=0;i<nStartPos.length;i++) 'wP\VCL2>
{ a*KJjl?k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H7R6Ljd?&S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), dfA4OZ&
nStartPos,nEndPos,i); $_0~Jzt,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]$ iqJL
fileSplitterFetch.start(); gye'_AR?k
} >KnXj7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]tDuCZA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <+${gu?^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @m(ja@YC
nEndPos = " + nFileLength); ;kiL`K
// fileSplitterFetch[nPos.length-1].start(); $56Z/*
!TdbD56
Umt?COc
//等待子线程结束 4?cIn4}
//int count = 0; Ok6c E
//是否结束while循环 ^# gR"\F`d
boolean breakWhile = false; "yc_*R(pU
^bDh[O
>ay% !X@3"
while(!bStop) IA?v[xu
{ b#z{["%Zp
write_nPos(); Y1h)0_0
Utility.sleep(500); x5)YZ~5
breakWhile = true; h`%}5})=
^SH8*7l7
Dwp-*QK^G
for(int i=0;i<nStartPos.length;i++) O!#bM< *
{ ()I';o
if(!fileSplitterFetch.bDownOver) 3Zeh$DZ
{ bQu1L>c,Uw
breakWhile = false; @{y[2M} %]
break; ley:=(
} auV<=1<zJ
} pSlosv(6
if(breakWhile) bB`p-1
break; MZInS:Vj
f)/5%W7n}
=]yzy:~ey
//count++; 'WLh D<
//if(count>4) GH!Lu\y\
// siteStop(); EvEI5/z
} E[N3`"
Y$ To)qo
XrD@q
System.err.println("文件下载结束！"); AUvUk<a
} 8@Kvh|
catch(Exception e){e.printStackTrace ();} \9GJa"xA`
} *D$[@-7
mUW4d3tE
9EqU 2~
//获得文件长度 1:r8p6
public long getFileSize() P7`sJ("#
{ */JMPw&
int nFileLength = -1; Y &"rf
try{ .W)%*~ O!;
URL url = new URL(siteInfoBean.getSSiteURL()); |X$O'Gf#n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Nn%[J+F
httpConnection.setRequestProperty("User-Agent","NetFox"); LU=`K4
:yTpjC-S]
pa@@S$(
int responseCode=httpConnection.getResponseCode(); "<y0D!&
if(responseCode>=400) 6!GO{2d"
{ OcWzo#q4[
processErrorCode(responseCode); W<AxctId
return -2; //-2 represent access is error orcPKCz|"
} gwyHDSo8:a
b^~"4fU
-'iV-]<
String sHeader; - P$mN6h
<+wbnnK
B5iVT<:a
for(int i=1;;i++) 8qY\T0
{ -U"h3Ye^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3h-C&C
//Utility.log(in.readLine()); !jeoB
sHeader=httpConnection.getHeaderFieldKey(i); !^:)zORYR
if(sHeader!=null) E 9LKVs}
{ D[5Qd)PIL
if(sHeader.equals("Content-Length")) wgb e7-{
{ [aF^D;o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }c$@0x;YQ
break; X!vBD
} 18xT2f
} dO{a!Ca
else quPNwNy
break; GYq.!d@O
} Qg\{d)X[N
} SQ_w~'(
catch(IOException e){e.printStackTrace ();} Bi'qy]%
catch(Exception e){e.printStackTrace ();} uGxh}'&
~rWys=
M' d ,TV[
Utility.log(nFileLength); pSvqGJU3
vl{G;[6
4._U
return nFileLength; pW>?%ft.
} y)B>g/Hoh
*)6:yn
GV1SKa
//保存下载信息（文件指针位置） ;MH<T6b
private void write_nPos() 6/Pw'4H9$
{ hrRkam!y
try{ +l "z
output = new DataOutputStream(new FileOutputStream(tmpFile)); t69C48}15
output.writeInt(nStartPos.length); OcBKn=8
for(int i=0;i<nStartPos.length;i++) t[ Zoe+&
{ {|;5P.,l
// output.writeLong(nPos); ,W!v0*uxp&
output.writeLong(fileSplitterFetch.nStartPos); >*hY1@N1
output.writeLong(fileSplitterFetch.nEndPos); X<OOgC
} {O4y Y=G
output.close(); g=T !fF=
} <]jKpJ{3N
catch(IOException e){e.printStackTrace ();} #@*;Y(9Ol
catch(Exception e){e.printStackTrace ();} X \1grM
} w[bhm$SX]B
^HYrJr$y
yv@td+-"D
//读取保存的下载信息（文件指针位置） sSM^net0
private void read_nPos() ^`96L
{ |V 3AA
try{ {g%F 3-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Dp5hr8bT
int nCount = input.readInt(); bP4<q?FKcN
nStartPos = new long[nCount]; 'k?%39
nEndPos = new long[nCount]; R*v~jR/
for(int i=0;i<nStartPos.length;i++) Oc|`<^m
{ )_vE"ryThA
nStartPos = input.readLong(); 7 fE QD?C
nEndPos = input.readLong(); ?-y!FD}m&
} \ nIz5J}3
input.close(); LZ97nvK
} km)5?
catch(IOException e){e.printStackTrace ();} &rcC7v K9
catch(Exception e){e.printStackTrace ();} /ynvQ1#uA
} HR/"Nwr
"o=*f/M
Vh.9/$xQ
private void processErrorCode(int nErrorCode) ^X&n-ui
{ rM sd)
System.err.println("Error Code : " + nErrorCode); [%8t~zg
} V8aLPJ0_
((2 g
h;^H*Y&`
//停止文件下载 2W}f|\8MX
public void siteStop() 3M;[.b
{ FXHcy:)}G
bStop = true; C;u8qVI
for(int i=0;i<nStartPos.length;i++) ,r&:C48dI
fileSplitterFetch.splitterStop(); Eagl7'x
>O{[w'sWa
7lo`)3mB
} k3-'!dW<
} ;oKN8vI#7
//负责部分文件的抓取 &I&:
**FileSplitterFetch.java XzX-Q'i=n0
*/ O[N}@%HMW
package NetFox; *bl*R';
$*%ipD}f
HF3W,eaqK
import java.io.*; b V)mO@N~w
import java.net.*; <$f7&6B
1YGj^7V)|Z
w $\p\}~,
public class FileSplitterFetch extends Thread { Tn$/9<Q
1@ e22\
ux[h\Tp
String sURL; //File URL rNdeD~\
long nStartPos; //File Snippet Start Position 0I8w'/s_g9
long nEndPos; //File Snippet End Position ,9(=Iu-?1
int nThreadID; //Thread's ID EXdx$I=X
boolean bDownOver = false; //Downing is over rRTAWAs%T
boolean bStop = false; //Stop identical J?yNZK$WqN
FileAccessI fileAccessI = null; //File Access interface [<HU~PP
nX@lR~g%F
KRY%B[k
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException h83;}>
{ 'u\my
this.sURL = sURL; Y7|R vLWoP
this.nStartPos = nStart; h:[8$]
this.nEndPos = nEnd; [7K-L6X
nThreadID = id; X-tc Ud
fileAccessI = new FileAccessI(sName,nStartPos);//定位 CaSoR |
} Ya#,\;dTT
6' 9ITA
o3_dHbdI
public void run() O4Wn+$AN
{ sHk,#EsKH
while(nStartPos < nEndPos && !bStop) 'nK(cKDIG
{ WBo|0(#
)FNvtLZ
'7+e!>"
try{ /[[_}\xI%
URL url = new URL(sURL); rmX'Ym9#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i\2d1Z
httpConnection.setRequestProperty("User-Agent","NetFox"); cJ6n@\
String sProperty = "bytes="+nStartPos+"-"; uxGY/Zf
httpConnection.setRequestProperty("RANGE",sProperty); =~)J:x\F
Utility.log(sProperty); X+'z@xpj
GI&XL'K&
=@98Gl9!
InputStream input = httpConnection.getInputStream(); Js`xTH'
//logResponseHead(httpConnection); *5SOXrvhu6
N36<EHq
S,K'y?6
byte[] b = new byte[1024]; SR,id B&i
int nRead; iIOA54!o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) UDJ{iZ
{ o%!8t_1mR
nStartPos += fileAccessI.write(b,0,nRead); :# 1d;jx
//if(nThreadID == 1) DNARe!pK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Kt(Z&@
} ?s4-2g
8"d0Su4r
C~16Jj:v
Utility.log("Thread " + nThreadID + " is over!"); =%p%+F@RlW
bDownOver = true; X[Lwx.Ly8
//nPos = fileAccessI.write (b,0,nRead); mN>7vJ
} q/ x(:yol
catch(Exception e){e.printStackTrace ();} d?j_L`?+
} C'HW`rh.^
} -P;_j,~U
*Q?ZJS~
*O>OHX
//打印回应的头信息 c: /Wk
public void logResponseHead(HttpURLConnection con) =")}wl=s
{ NVEjUt/
for(int i=1;;i++) J3oEN'8S
{ CNC3">Dk~9
String header=con.getHeaderFieldKey(i); MYQZqlV
if(header!=null) fS08q9,S/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l8I`%bu
Utility.log(header+" : "+con.getHeaderField(header)); P@gVzx)M
else vvJ{fi
break; 7M#eR8*[se
} `>M-J-J
} &RRHmJI:
R3nCk-Dq
V SJGp`
public void splitterStop() _:hrm%^
{ o,| LO$~
bStop = true; Ls8@@b,t2
} pwg$% lv
[>5<&[A
=x9SvIm/tH
} axJuJ`+Y
+.Pv:7gh
kA`Z#yu
/* ?F{sym@i
**FileAccess.java AJk0jh\.j%
*//文件访问(定位，写) -f&16pc1t
package NetFox; l^.d3b
import java.io.*; +_.k\CRms
T&M*sydA
g"k1O
public class FileAccessI implements Serializable{ (G:A^z
^/nj2"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 qJjXN+/D
RandomAccessFile oSavedFile; ws"{Y+L
long nPos; 3V)ef$Y0
uvNLm]*
'q158x
public FileAccessI() throws IOException C,*3a`/2M^
{ ;[-OMGr]#
this("",0); s}2TJa
} nz{ ;]U1
9YpgzCx Z
U3Fa.bC6}
public FileAccessI(String sName,long nPos) throws IOException G.2\Sw
{ jZjWz1+
oSavedFile = new RandomAccessFile(sName,"rw"); L1'PQV
this.nPos = nPos; a`c#- je
oSavedFile.seek(nPos); b3/@$x<
} SM57bN
C`G+b{o
zD#$]?@ b
public synchronized int write(byte[] b,int nStart,int nLen) 5yOIwzr&Uu
{ A -C.Bi;/
int n = -1; F$L2bgQR?'
try{ [HRry2#s
oSavedFile.write(b,nStart,nLen); _&(\>{pm
n = nLen; o#"U8N%r
} mLEJt,X
catch(IOException e) /{)}y
{ :G.u{cw
e.printStackTrace (); +8<|P&fH
} BiFU3FlTf
UL{+mp
OD@k9I[
return n; OC?a[^hB^)
} [b2KBww\
EZ,Tc;f=
!.2tv
} 7 KuUV!\h`
Zz,j,w0 Z
*F<Ar\f5
/* ZVelKI8>
**SiteInfoBean.java ~U;M1>
*/ aru;yR
package NetFox; 1bz%O2U-(
c-jE1y<
Sg&0a$
public class SiteInfoBean { Cs!z3QU
k)3b0T@b
,`pUz[wl
private String sSiteURL; //Site's URL T'ko =k
private String sFilePath; //Saved File's Path /"J3hSR
private String sFileName; //Saved File's Name C vOH*K'
private int nSplitter; //Count of Splited Downloading File )%+7"7.
(DIMt-wz
kTW[)
public SiteInfoBean() qWdob>u
{//nSplitter的缺省值为5 g[c_rty
//default value of nSplitter is 5 5cF7w
this("","","",5); Y9}ga4
} ]lqe,>
h@2YQgw`
JBI>D1`"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ip+?k<]z
{ I^GZ9@UE
sSiteURL= sURL; CcJ%;.V,T
sFilePath = sPath; <#ng"1J
sFileName = sName; WvoJ^{\4N*
this.nSplitter = nSpiltter; NZu2D
T;M4NGmvd
HhZ>/5'(
} 9dO. ,U*`
5M&<tj/[a0
Z#t}yC%^d
public String getSSiteURL() [*K.9}+G_
{ ~]Weyb[N
return sSiteURL; 8x`EUJ
} rYCIU
-NPX;e$<
.[:y`PCF
public void setSSiteURL(String value) mVd%sWD
{ h:=W`(n5u
sSiteURL = value; WB.w3w[f
} _[pbfua
(:>Sh0.
v;nnr0;
public String getSFilePath() |/%X8\
{ NtG^t}V
return sFilePath; a|-ozBFR
} ?&JKq^9\I
u\3=m%1
\'6%Ld5km
public void setSFilePath(String value) $}JWJ\-]
{ 2Ah B)8bG
sFilePath = value; HE:]zH
} lNo]]a+_
5 )z'=
&S=xSs:q.
public String getSFileName() {#,?K
{ 2f5YkmGc";
return sFileName; R9-Uoc/
} @6Z6@Pq(xQ
(H;,E-
! JauMR
public void setSFileName(String value) 1oI2
{ r<[G~n
sFileName = value; :{ Lihe~\
} lvH} 8lJ
D$Ao-6QE W
fuT Bh6w&
public int getNSplitter() y=2nV
{ MDoV84Fh
return nSplitter; ojx2[a\
} A3.*d:A
_ZE&W
!8|?0>3)
public void setNSplitter(int nCount) K$wxiGg8P
{ > .K
nSplitter = nCount; Pp.]/;
} V6&6I
} :)F0~Q
"%w E>E
= Atyy
/* A&{eC C
**Utility.java sZ0)f!aH:_
*/ $mxl&Qr>Q;
package NetFox; y;fnC5Q
C[CNJ66
U2 Cmf
public class Utility { I:M15
aWY#gI{
Oo/@A_JO@
public Utility() a&Me#H{
{ eC@b-q
/k KVIlO
}Vfc;2
} i^)JxEPr w
esd9N'.Q*
//线程睡眠 tlgg~MViS
public static void sleep(int nSecond) 4$+/7I \
{ s0'6r$xj
try{ v!#koqd1y.
Thread.sleep(nSecond); 2]Ei4%jo
} k/i&e~! \
catch(Exception e) M %!O)r#Pn
{ ZQyXzERp
e.printStackTrace (); \*Z:w3;r
} U%)*I~9
} HMw}pp:
-kb;h F}.
//日志 ITZ}$=
public static void log(String sMsg) A~;+P
{ - H`,`#{
System.err.println(sMsg); M&KJZ
} yY!@FGsA
~JB4s%&
R#Z m[S
public static void log(int sMsg) "5"{~3Gw^
{ ,qIut|C*
System.err.println(sMsg); 4{%-r[C9k
} 5s<.qDc
} !!6g<S7)
1~S''[
#66u<FaG
/* JTTI`b2l_
**TestMethod.java EV_u8?va
*/ ODKS6E1{
package NetFox; [@0Hmd7
5KW n>n
,<;.'r
public class TestMethod { yS4nB04`=
?}No'E1!I
} A}Vd:#
public TestMethod() IeB^BD+j
{ ///xx/weblogic60b2_win.exe <q=]n%nX
try{ 6\x/Z=}L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =g)SZK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); MpJ]1
SiteFileFetch fileFetch = new SiteFileFetch(bean); @"afEMd
fileFetch.start(); /brHB @$
} *7C l1o
catch(Exception e){e.printStackTrace ();} uC?/p1
z=TuUl@
>|hqt8lY
} MaP-
%Z yt;p2
gh%Q9Ni-
public static void main(String[] args) D;Y2yc[v
{ 9)'wgI#
new TestMethod(); rR(\fX!dg
} Z )X(
} =64Ju Wvo
点击下载更多相关资料