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)); S9'8rn!_
} $cUTe
for(int i=0;i<nEndPos.length-1;i++) X=Th
{ 'Itsu~fza
nEndPos = nStartPos[i+1]; >#jfZ5t
} Ba]J3Yp,z
nEndPos[nEndPos.length-1] = nFileLength; uBPxMwohR
} l-GQ AI8
} /%'>?8/
@&7|Laa
zURob MpE#
//启动子线程 6)QJms
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |KM<\v(A{
for(int i=0;i<nStartPos.length;i++) p?q~.YY
{ R>05MhA+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qit D{;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), y&$mN
nStartPos,nEndPos,i); S<+/Ep 2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AZi|85rN
fileSplitterFetch.start(); K:i{us`
} mROXwzL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c,\!<4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \vU1*:3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Wg3\hv29
nEndPos = " + nFileLength); ~S='~ g)
// fileSplitterFetch[nPos.length-1].start(); 6tKm'`^z4
~jqG
0A7 qO1%xw
//等待子线程结束 I`O)I&KH
//int count = 0; tk"+PTGJT
//是否结束while循环 4IW7^Pq`P
boolean breakWhile = false; :=I@<@82W
-X)KY_Xn@/
XehpW}2\
while(!bStop) @7C?]/8#
{ `k>h2(@9S
write_nPos(); FK8GBkQ!
Utility.sleep(500); `(RQh@H
breakWhile = true; RH=Tu6i
BgzER[g|q{
\8I>^4t'/
for(int i=0;i<nStartPos.length;i++) C9`J6Uu
{ K1F,M9 0]
if(!fileSplitterFetch.bDownOver) &?-LL{W{
{ -}h+hS50F
breakWhile = false; vw'`t6
break; NvZ )zE
} axRzn:f
} k>N >_{\
if(breakWhile) PhS`,I^Z
break; NVTNjDF%s
-RSPYQjz
]lKQwpX3
//count++; *TjolE~o
//if(count>4) T2nbU6H
// siteStop(); 7H1 ii
} E27N1J+1
;U +;NsCH
yWs_Z6b
System.err.println("文件下载结束！"); ~"Pu6-\VT
} `@Q%}J
catch(Exception e){e.printStackTrace ();} ~BNLzt3%O
} w_gPX0N}3n
!_EaF`oh(
i&r56m<
//获得文件长度 3E!#?N|v
public long getFileSize() XYKWOrkQqa
{ 7*7Z&1*3
int nFileLength = -1; j:yQP#U
try{ rt7Ma2tK
URL url = new URL(siteInfoBean.getSSiteURL()); ]aqHk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qo4+=^(
httpConnection.setRequestProperty("User-Agent","NetFox"); k{fCU%
z)Y<@2V*C
wW7W+,{o
int responseCode=httpConnection.getResponseCode(); pP4i0mO{Dv
if(responseCode>=400) 3lyk/',
{ N}Ol`@@#h
processErrorCode(responseCode); JY\8^}'9
return -2; //-2 represent access is error h48JpZ"
} :J3ZTyjb
8-N8v *0
RaKfYLw
String sHeader; 4{:W5eT!/
$II[b-X?S
YHVJg?H3
for(int i=1;;i++) O};U3=^0f
{ AnbY<&OC1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); o@?3i+%}8
//Utility.log(in.readLine()); d(>7BV
sHeader=httpConnection.getHeaderFieldKey(i); mulK(mp
if(sHeader!=null) <p48?+K9
{ ~zklrBn&
if(sHeader.equals("Content-Length")) +\`D1d@
{ UF[2Rb8?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); sckyG
break; 58H[sM4>
} w1J&c'-
} wff&ci28
else &&0,;r,-)
break; |(gq:O
} t'uZho~^F
} Lp; {&=PIo
catch(IOException e){e.printStackTrace ();} c2}?[\U]
catch(Exception e){e.printStackTrace ();} dOm#NSJVd
f`5e0;zm
vG(Gs=.U
Utility.log(nFileLength); iOB]72dh
|~mi6 lJ6
M DnT
return nFileLength; })V9d
} ^A8'YTl
or_x0Q
qll)
//保存下载信息（文件指针位置） ckqU2ETpD}
private void write_nPos() \*}JdEHB
{ pV:c`1\`
try{ d}K"dr:W5
output = new DataOutputStream(new FileOutputStream(tmpFile)); SRl:+!@.
output.writeInt(nStartPos.length); }5H3DavW
for(int i=0;i<nStartPos.length;i++) 6#xP[hlR[
{ 7xP>AU)y
// output.writeLong(nPos); 0`=#1u8
output.writeLong(fileSplitterFetch.nStartPos); *P_ 3A:_
output.writeLong(fileSplitterFetch.nEndPos); DLYk#d: q?
} k zhek >
output.close(); x+zz:^yHYf
} .*u, !1u
catch(IOException e){e.printStackTrace ();} nXDU8|"
catch(Exception e){e.printStackTrace ();} AZ)H/#be
} @[0zZX2EE
m~%\f8w-x
p=U*4[9k
//读取保存的下载信息（文件指针位置） ;z;O}<8s
private void read_nPos() i,R<`K0
{ fX).A`
try{ \ajy%$;$}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7:U^Ki
int nCount = input.readInt(); G#ov2
nStartPos = new long[nCount]; <4z |"(
nEndPos = new long[nCount]; B$aA=+<S
for(int i=0;i<nStartPos.length;i++) ?Kw~O"L8
{ {n8mE,;M
nStartPos = input.readLong(); 'AN3{
nEndPos = input.readLong(); "d'D:>z]%
} 'rJkxU{
input.close(); A4.Q\0
} WJ$D]7
catch(IOException e){e.printStackTrace ();} * B!uYP
catch(Exception e){e.printStackTrace ();} YC#N],#
} j )6A
fu3/n@L
_}.BZ[i
private void processErrorCode(int nErrorCode) MtC\kTW
{ K!6k<
System.err.println("Error Code : " + nErrorCode); G(F}o]
} q/,>UtRr
53d8AJ_@X
{-IH?!&v
//停止文件下载 5BCHWX*y
public void siteStop() 12;"=9e!
{ ^>02,X mk
bStop = true; )Xxu-/-
for(int i=0;i<nStartPos.length;i++) !6:kJL}U
fileSplitterFetch.splitterStop(); RiC1lCE
LutP&Ebt8
{)]5o| Hx
} GGcNaW'
} 8%]o6'd4
//负责部分文件的抓取 qc_c&
**FileSplitterFetch.java 62~8>71;'
*/ W'x/Kg,w-
package NetFox; 7Z0fMk
mt$0p|B8
v'(p."g
import java.io.*; bcFG$},k
import java.net.*; e[f}Lxln
E}K6Op;=v5
>[;+QVr;
public class FileSplitterFetch extends Thread { 2Z 4Ekq0@
OnE#8*8
iB1"aE3
String sURL; //File URL pIBL85Xe
long nStartPos; //File Snippet Start Position F)'kN2
long nEndPos; //File Snippet End Position m,KG}KX
int nThreadID; //Thread's ID XVcY?_AS#
boolean bDownOver = false; //Downing is over (LzVWz m
boolean bStop = false; //Stop identical Lu,72i0O ^
FileAccessI fileAccessI = null; //File Access interface Tg|0!0qD]F
9~i=Af@
"w.gP8`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;5qZQ8`4
{ oUrNz#U
this.sURL = sURL; Vvk1 D(
this.nStartPos = nStart; 'E FP/(2J
this.nEndPos = nEnd; 555j@
nThreadID = id; ,83%18b
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?5(Cwy ?
} T$[50~
w.w(*5[
t]LOBy-Kv
public void run() !5lb+%7
{ gE$D#PZa
while(nStartPos < nEndPos && !bStop) xi|T7,\X
{ fz'@ON
%O]]La
7M;7jI/C
try{ yO\.dp
URL url = new URL(sURL); 8,unq3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8D3|}z?
httpConnection.setRequestProperty("User-Agent","NetFox"); M?mPi 3
String sProperty = "bytes="+nStartPos+"-"; M4[(.8iE
httpConnection.setRequestProperty("RANGE",sProperty); ,@1rP55
Utility.log(sProperty); ZoJ_I >uv
[?z`XY_-
~JhH ,E
InputStream input = httpConnection.getInputStream(); T%|{Qo<j
//logResponseHead(httpConnection); IiW*'0H:/
~n9x ,
E Dh$UB)
byte[] b = new byte[1024]; vz'/]E
int nRead; XFJGL!wWm[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jpijnz{M
{ @@->A9'L
nStartPos += fileAccessI.write(b,0,nRead); i+rh&,
//if(nThreadID == 1) ]\DZW4?'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [t#xX59
} 8NCu;s
66ULR&D8
ejs_ ?
Utility.log("Thread " + nThreadID + " is over!"); L\;n[,.
bDownOver = true; ndW]S7
//nPos = fileAccessI.write (b,0,nRead); _{$eOwB
} r"HQ>Wn
catch(Exception e){e.printStackTrace ();} "u29| OY
} pjG/`
} (%p@G5GU
f_\,H|zco)
yhTC?sf<
//打印回应的头信息 t5t!-w\M$+
public void logResponseHead(HttpURLConnection con) FFC"rG
{ ~)ut"4
for(int i=1;;i++) VINb9W}G[
{ 8NP|>uaj
String header=con.getHeaderFieldKey(i); |.]sL0;4Z
if(header!=null) 3i\<#{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mO#62e4C
Utility.log(header+" : "+con.getHeaderField(header)); ,%Go.3i[
else _=Y?' gHH
break; 4v[Zhf4JM
} ?rauhTVnJ
} @J~hi\&`
e'nhP
/i:c!l9
public void splitterStop() a ][t#`
{ !i4/#H
bStop = true; Lp1\vfU<+
} sKu/VAh x
+g.lLb*#
g/3t@7*<
} <D}yqq@|
5N~JRq\
'tJb(X!]q
/* PvHX#wJ
**FileAccess.java #!yW)RG
*//文件访问(定位，写) ;q5.\m:
package NetFox; pDYcsC{p
import java.io.*; rf\/Y"D
Kg8n3pLAX
8bTE#2+-
public class FileAccessI implements Serializable{ gPJZpaS
.#Vup{.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Al}D~6MD
RandomAccessFile oSavedFile; Sv#S_jh
long nPos; !_i;6UVG
QZZt9rA;
V'iT>
public FileAccessI() throws IOException Y%zYO
{ [\BLb8
this("",0); B!j7vXM2
} #ULjK*)R
$R&K-;D/8
EX"o9'
public FileAccessI(String sName,long nPos) throws IOException k`(Cwp{Oc
{ V'M#."Of/
oSavedFile = new RandomAccessFile(sName,"rw"); *!5X!\e_
this.nPos = nPos; *4HogC
oSavedFile.seek(nPos); n.l7V<1
} H*KZZTKd
W ])Lc3X
JmBe1"hs
public synchronized int write(byte[] b,int nStart,int nLen) oVAY}q|wU
{ 1`q>*S](
int n = -1; n=iL6Yu(
try{ qK-\`m
oSavedFile.write(b,nStart,nLen); &x.n>O
n = nLen; YQ$Wif:@(n
} eeM$c`Y<
catch(IOException e) YiGSFg
{ c,L{Qv"n{
e.printStackTrace (); Ljs4^vy<J
} v!WkPvU
=6O<1<[y
zd0[f3~
return n; 38zG[c|X
} /w/um>>K.
GNX`~%3KYc
-qs R,H
} L"[>tY
3uy^o
GOU>j"5}2
/* 5sZqX.XVF
**SiteInfoBean.java vxZ :l
*/ }}X<e
package NetFox; N@x5h8
W6&mXJ^3L
g;-6Hg'
public class SiteInfoBean { I&Z+FL&@f
d>gN3}tT
.|c=]_{
private String sSiteURL; //Site's URL [,TK"
private String sFilePath; //Saved File's Path o?`^ UG-
private String sFileName; //Saved File's Name L7"B`oa(p
private int nSplitter; //Count of Splited Downloading File ^@f-Ni\
:=oIvSnh
L)QAI5o:3
public SiteInfoBean() ,sZ)@?e
{//nSplitter的缺省值为5 m#|h22^H
//default value of nSplitter is 5 /VHQ!Wi
this("","","",5); 4NDT5sL
} }!^`%\ %\
t2_pwd*B
B!AJ*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8;<3Tyjzu
{ "NvB@>S
sSiteURL= sURL; G_v^IM#B=
sFilePath = sPath; ojbms>a
sFileName = sName; i~ITRi@
this.nSplitter = nSpiltter; 7*C>4Gs
W%P$$x5&
t2hI^J0y
} <d~IdK'\x
Fx3X
5c 69M5
public String getSSiteURL() qk_YFR?R
{ Z"N}f ,
return sSiteURL; vT;~\,M
} Cm%xI&Y
7*(K%e"U
9D{p^hd
public void setSSiteURL(String value) ;.I,R NM
{ lnWscb3t
sSiteURL = value; =y]FcxF
} !f01.Tq8
+z O.|`+
|wkUnn4UB8
public String getSFilePath() \xjI=P'-25
{ %ou@Y`
return sFilePath; <G /a-Z
} cIQe^C
3Bbd2[<W
4;)aGN{e
public void setSFilePath(String value) Psw<9[
{ NxrfRhaU3
sFilePath = value; 3Q2z+`x'
} TQ69O +
H:4?sR3
gV;9lpZ2
public String getSFileName() H|s,;1#
{ 5NN`tv
return sFileName; eD)@:K
} :$^cY>o
c3!YA"5
r#\Lq;+-B
public void setSFileName(String value) qs3V2lvYw{
{ ;G4g;YHy|
sFileName = value; OY,iz
} |*JMCI@Mz
GEJy?$9
;GZ/V;S
public int getNSplitter() Fm`c
{ fa2hQJ02
return nSplitter; f<LRM
} aB2t/ua
!"bU|a
-^WW7 g`
public void setNSplitter(int nCount) W3y9>]{x^
{ [_1K1i"m
nSplitter = nCount; li
} fT0+inRG
} cjc1iciZ
>{.|Ng4K
Fh~ pB>t
/* L%31>)8
**Utility.java 6rh^?B
*/ H57wzG{xG
package NetFox; `8b4P>';O'
n|) JhXQ
p#>d1R1&
public class Utility { MxLi'R=
N6w!V]b
i?]`9z
public Utility() }q=uI`
{ #8i9@w
)5Ofr-Y
!f)^z9QX8
} 4C`p`AQqpQ
MOIMW+n
//线程睡眠 _)-y&
public static void sleep(int nSecond) 3?uah'D5
{ O%m>4OdH
try{ 3\H0Nkubts
Thread.sleep(nSecond); OHK]=DH:M
} Ry"N_Fb
catch(Exception e) 905Lk>rB
{ b&I{?'"%8
e.printStackTrace (); mM\jU5P:^
} hDD]Kc;G^1
} O[\obi"}
;]Ko7M(4
//日志 ;\rKkH"K8n
public static void log(String sMsg) {:ZsUnzm
{ FSA"U9 w<
System.err.println(sMsg); aJSBG|IC
} 9 M!U@>
K%3{a=1
SoNT12>
public static void log(int sMsg) QO <.l`F
{ 3;f}w g
System.err.println(sMsg); 'FwNQzzt
} uM@ve(8\
} x|U[|i,;
/}R*'y
#mW#K
/* TA>28/U#
**TestMethod.java *IV_evgM7
*/ TmUN@h
package NetFox; 1 2J#}|
"cx#6Bo|
:qrCqFl
public class TestMethod { r"x/,!_E
on)$y&lu
BOWR}n!g
public TestMethod() `m=u2kxY
{ ///xx/weblogic60b2_win.exe 'h{| ]
try{ :{M1]0NH
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X$9 "dL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +=g9T`YbE
SiteFileFetch fileFetch = new SiteFileFetch(bean); (VB-5&b
fileFetch.start(); NG\^>.8
} ">!<OB
catch(Exception e){e.printStackTrace ();} ILMXWw
7N}==T89[
faPgp
} IT0 [;eqR
\4"01:u'
mH5[(?
public static void main(String[] args) 95b65f
{ kC=h[<'
new TestMethod(); be+tAp`
} D5jZ;z}
} o 12wp
点击下载更多相关资料