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)); ap"pQ[t;
} F}1._I`-
for(int i=0;i<nEndPos.length-1;i++) 1\)lD(J\C
{ 6BEDk!
nEndPos = nStartPos[i+1]; ,^eOwWV
} *Ue#Sade
nEndPos[nEndPos.length-1] = nFileLength; yw89*:A6
} :QXKG8^
} aMJ2bu
"s(|pQh;
U^qS[HM
//启动子线程 z92Xc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4-$kcwA
for(int i=0;i<nStartPos.length;i++) =e9<.{]S/
{ S?VKzVDB.S
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ej=}OH4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), t\Qm2Q)>
nStartPos,nEndPos,i); :lmimAMt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eW}-UeT
fileSplitterFetch.start(); :7(d6gEL
} %dhrXK5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wub7w#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); N$.ls48a4-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |8GLS4.]t
nEndPos = " + nFileLength); ZU2D.Kf_:
// fileSplitterFetch[nPos.length-1].start(); ;4Xx5*E
")nKFs5
\nL@P6X
//等待子线程结束 'GO*6$/
//int count = 0; J{Ld)Q,^
//是否结束while循环 N.SV*G @
boolean breakWhile = false; z=8l@&hYLq
K 6,c||#<
]"j%:fr
while(!bStop) .G"T;w6d
{ `R lWhdE
write_nPos(); ,jD-fL/:
Utility.sleep(500); 0}T56aD=!
breakWhile = true; =CCddLO
s!Iinc^p
dwiLu&]u
for(int i=0;i<nStartPos.length;i++) 9C5F#(uY
{ y S<&d#:"
if(!fileSplitterFetch.bDownOver) :r{W)(mm
{ 0TiDQ4}i[
breakWhile = false; u~mpZ"9$ 3
break; JxM32?Rm*w
} RtDTcaW/
} Wv,?xm
if(breakWhile) Vn_>c#B
break; [DTe
<Oy2JjY
&[yYgfsp
//count++; zhyf}Ta'
//if(count>4) Q2Uk0:M
// siteStop(); :&E~~EUW
} wGHVq fm5
L%pAEoSG
eq9qE^[Z&
System.err.println("文件下载结束！"); UCo<ie\V
} +]hc!s8
catch(Exception e){e.printStackTrace ();} |47 2X&e
} p-7?S^!l
piIGSC
t6)R37
//获得文件长度 (;HO3Z".q$
public long getFileSize() ]a:T]x6'
{ l[nf"'
int nFileLength = -1; .l,NmF9
try{ =~dsIG
URL url = new URL(siteInfoBean.getSSiteURL()); 7a.iT-*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1d&Q E\2}
httpConnection.setRequestProperty("User-Agent","NetFox"); R F;u1vEQ8
\z.p [;'ir
i2LN`5k
int responseCode=httpConnection.getResponseCode(); |Y2n6gkH[
if(responseCode>=400) z34+1d
{ V9`jq$
processErrorCode(responseCode); ^[2siG
return -2; //-2 represent access is error +bWo{
} \PmM856=ms
}F3}"Ik'L
t*c_70|@k
String sHeader; |Y(
%XXjQ5p
BbzIQg:
for(int i=1;;i++) 2k`Q+[?{q>
{ L|A1bxt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \@_?mL@=
//Utility.log(in.readLine()); 2nSz0 .
sHeader=httpConnection.getHeaderFieldKey(i); 5ai$W`6
if(sHeader!=null) !B#tJD
{ @ZcI]G%
if(sHeader.equals("Content-Length")) 8%b-.O:_$
{ Uz`OAb
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |j$$0N
break; YD5mJ[1t"2
} EDA6b]
} krXU*64
else R~#&xfMd.
break; 2y9$ k\<xV
} [?)He} _L
} 4&B|rf
catch(IOException e){e.printStackTrace ();} h<BTu7a`r
catch(Exception e){e.printStackTrace ();} cvV8;
3X1 U
h-*h;Uyc
Utility.log(nFileLength); $oi8<8Y
QEY#U|
In}~bNv?
return nFileLength; Gn%k#
} ,k,+UisG
,WS{O6O7
kM(,8j
//保存下载信息（文件指针位置） tLGNYW!K
private void write_nPos() 9]a!1
{ V:1_k"zQ
try{ 8oP"?ew#
output = new DataOutputStream(new FileOutputStream(tmpFile)); FF30VlJ
output.writeInt(nStartPos.length); RM!VAFH
for(int i=0;i<nStartPos.length;i++) <!~NG3KW[>
{ !7Z?VEZ
// output.writeLong(nPos); 8fQXif\z
output.writeLong(fileSplitterFetch.nStartPos); s&-dLkis{u
output.writeLong(fileSplitterFetch.nEndPos); G5$YXNV
} 3O?[Yhk`.
output.close(); zUJPINDb
} y~rtYI
catch(IOException e){e.printStackTrace ();} ztV%W6
catch(Exception e){e.printStackTrace ();} H`jvT]
} HhB' ^)
Xm^/t#
r59BBW)M
//读取保存的下载信息（文件指针位置） uBo~PiJ2"
private void read_nPos() ?qczMck_
{ `xFgYyiQd
try{ \l/<[ZZ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "'U]4Z%q!
int nCount = input.readInt(); ;)!);q+
nStartPos = new long[nCount]; X"v)9p
nEndPos = new long[nCount]; jN sM&s,
for(int i=0;i<nStartPos.length;i++) $Q56~AP
{ 1h&_Q}DM
nStartPos = input.readLong(); ?xzDz
nEndPos = input.readLong(); 8"J6(KS
} 8|IlJiJ~v
input.close(); AF"XsEt.e
} 3>G"&T{
catch(IOException e){e.printStackTrace ();} HmRmZ3~
catch(Exception e){e.printStackTrace ();} 3qwSm<
} ag"Nf-o/Y
Hr;\}
Rj/y.g
private void processErrorCode(int nErrorCode) 78FK{Cr
{ MK, $#
System.err.println("Error Code : " + nErrorCode); Ve\P,.
} LKu ,H
g42Z*+P6N
*vIC9./
//停止文件下载 NpF)|Ppb{
public void siteStop() =42NQ{%@;
{ lxOUV?m^N
bStop = true; @z7$1pl}
for(int i=0;i<nStartPos.length;i++) fZrB!\Q
fileSplitterFetch.splitterStop(); 3("E5lI(g:
2)jf~!o)Z
.7MLgC;
} ,HfdiGs}j
} hquN+eIDH
//负责部分文件的抓取 &W-1W99auE
**FileSplitterFetch.java Y .\<P*iO
*/ #l-/!j
package NetFox; >d5L4&r
N1espc@j
xs$-^FnD
import java.io.*; -bQi4
import java.net.*; D 13bQ&\B-
n_46;lD
}n$I #G}\/
public class FileSplitterFetch extends Thread { F}=O Mo:.
)VFS&|#\
-v62 s
String sURL; //File URL Z^ }4bR]
long nStartPos; //File Snippet Start Position a3[lZPQe
long nEndPos; //File Snippet End Position ]`_eaW?Ua
int nThreadID; //Thread's ID '' Pfs<!
boolean bDownOver = false; //Downing is over xY1@Ja
boolean bStop = false; //Stop identical $5Tjo T
FileAccessI fileAccessI = null; //File Access interface HWi: CDgm
1agI/R
(pkq{: Fs
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m15> ^i^W
{ Q@? {|7:
this.sURL = sURL; v!%VH?cA8
this.nStartPos = nStart; Ai.^~#%X
this.nEndPos = nEnd; [,|;rt\o>
nThreadID = id; @RFJe$%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5{O9<~,
} &L4>w.b"N
$' >|r]
5!}fd/}Uk
public void run() @sLB _f
{ C9"yu&l
while(nStartPos < nEndPos && !bStop) :ej`]yK |
{ !:9s>0';N
T96M=?wh!
J#*R]LU|
try{ H"J>wIuGX
URL url = new URL(sURL); -%6Y&_5VK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <;':'sW
httpConnection.setRequestProperty("User-Agent","NetFox"); LXx`Vk>ky
String sProperty = "bytes="+nStartPos+"-"; K:8. Dvn
httpConnection.setRequestProperty("RANGE",sProperty); Wc!.{2
Utility.log(sProperty); `Uy'YfYF
b{hdEb
NGOyd1$7N
InputStream input = httpConnection.getInputStream(); D}A>`6W<
//logResponseHead(httpConnection); bx=9XZ9g
n`2LGc[rP
?emYLw
byte[] b = new byte[1024]; +a!uS0fIJi
int nRead; [pYjH+<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 71!'k>]h
{ `} :~,E
nStartPos += fileAccessI.write(b,0,nRead); 8/`ij?gn
//if(nThreadID == 1) h^=9R6im
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RoeLf Ow
} b 3i34,
GP;UuQz
@86?!0bt
Utility.log("Thread " + nThreadID + " is over!"); ])iw|`@dJ
bDownOver = true; TxXX}6
//nPos = fileAccessI.write (b,0,nRead); Nvj0MD{ X
} a5@XD_b
catch(Exception e){e.printStackTrace ();} Y[Kpd[)[v
} [3fmhc
} LQ3J$N
o`<ps$yT
NG?-dkD
//打印回应的头信息 $|pD}
public void logResponseHead(HttpURLConnection con) .l}oxWWoS
{ 6R+EG{`
for(int i=1;;i++) C}8 3t~Q
{ ~#y(]Xec2
String header=con.getHeaderFieldKey(i); GBo'=
if(header!=null) vfPIC!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 't<hhjPqY
Utility.log(header+" : "+con.getHeaderField(header)); ISALR{Aq
else +[Zcz4\9
break; XL!^tMk
} d<+@cf_9
} i*2l4
O(CmdSk,
fs;pX/:FR
public void splitterStop() K6M_b?XekA
{ mqk tM6
bStop = true; )9'Zb`n
} do&0m[x%
}hA h'*(
z((9vi W
} O)?
/Ym!%11`
\>nY%*
/* 32Jl|@8,g
**FileAccess.java 2"C,u V@F!
*//文件访问(定位，写) >a$b4 pvh
package NetFox; mH)th7
import java.io.*; y~/i{a;1y
sm96Ye{O{
F`U YgN
public class FileAccessI implements Serializable{ ZKco
Z&Ao;=Gp1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JDj^7\`
RandomAccessFile oSavedFile; ;/|3U7{c
long nPos; 5B,HJax
V^5Z9!
1H]E:Bq
public FileAccessI() throws IOException Dh~Z8!*
{ C8bv%9
this("",0); n9x&Ws;
} 7UA|G2Zr
vB;$AFh{
h(Ccm44
public FileAccessI(String sName,long nPos) throws IOException w\2yippI
{ kFo&!
oSavedFile = new RandomAccessFile(sName,"rw"); ^":Dk5gl
this.nPos = nPos; Jk3V]u
oSavedFile.seek(nPos); &nX,)"
} *&sXC@^@^
?)V}_%fVv
DA-W =Cc
public synchronized int write(byte[] b,int nStart,int nLen) aB+B1YdY"
{ hDc)\vzr
int n = -1; q26%Z)'nf
try{ .?CumaU
oSavedFile.write(b,nStart,nLen); AiE\PMF~{P
n = nLen; >(:b\*C
} JU\wvP5j
catch(IOException e) Owz.C_{)
{ jYi{[**
e.printStackTrace (); KQ\d$fX
} 9}DF*np`G
*N|s+
n]+v Eu|
return n; 6ISDY>p
} *S$`/X
Z/>0P* F
:\+\/HTbh
} dxIt.h
GY;q0oQ,
A}cGag+sp
/* fW'U7&O
**SiteInfoBean.java Jxy94y*
*/ 7/$s!pV
package NetFox; >4lT0~V/
(xhwl=MX)
2AZ)|dM'`
public class SiteInfoBean { u/8urxpy
|vY0[#E8&
umo@JWr
private String sSiteURL; //Site's URL _^)<d$R<
private String sFilePath; //Saved File's Path ;Pi-H,1b
private String sFileName; //Saved File's Name 0{GpO6!
private int nSplitter; //Count of Splited Downloading File P,[O32i#
g@jAIy]
P95A_(T=[
public SiteInfoBean() *NDM{WB|)
{//nSplitter的缺省值为5 *Tt*\ O
//default value of nSplitter is 5 o?$B<Cb"
this("","","",5); """gV)Y
} & M wvj
oT\u^WU
Evn=3Tw
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Pkbx/\
{ 6SIk,Isy8
sSiteURL= sURL; >_4Ck{^d#
sFilePath = sPath; u(s/4Lu
sFileName = sName; x{X(Y]*1S
this.nSplitter = nSpiltter; z|V5/"
>7VOytc
lo*)%fy
} Z/wKUK;
cv b:FK
L]goHs
public String getSSiteURL() y@kRJ 8d
{ Qv%"iSe~J
return sSiteURL; na&?Cw
} -];/*nl
^0/FZ)V8
R`wL%I!?f
public void setSSiteURL(String value) 3+_ .I{
{ "i\rhX
sSiteURL = value; 0Jh^((i*
} W -Yv0n3
.X;zEyd
2Qqk?;^1
public String getSFilePath() xm}9(EJ
{ fAu^eS%>7
return sFilePath; (6R^/*-o
} HWJ(O/N
cY|?iEVs)
@O/Jy2>3H
public void setSFilePath(String value) bqHR~4 #IR
{ W)dQyZ>J
sFilePath = value; I+,~pmn:
} G[}$s7@k
lLO|,
)uvs%hK
public String getSFileName() W=fw*ro
{ |F }y6 gH
return sFileName; j {w'#x,
} c/Fy1Lv\
$niJw@zC
@5!Mr5;
public void setSFileName(String value) ^t&S?_DSZ
{ nyyKA_#:5
sFileName = value; mXd,{b'
} $4^cbk
=.=4P~T&
zW^_w&fd^j
public int getNSplitter() Yv?nw-HM
{ @6eM{3E.
return nSplitter; {sn RS)-
} WaY_{)x
\K$9r=!(
:DI``]Si\
public void setNSplitter(int nCount) SV2DvrIR
{ Zd~'%(q
nSplitter = nCount; #wXq'yi
} !~+"TI}_%w
} = GN1l[X
D=hy[sDBw
&cnciEw1
/* 4e6x1`Y{xB
**Utility.java v6Vieo=
*/ ^P4q6BW
package NetFox; S$ u`)BG):
PtH>I,/
N03)G2
public class Utility { =Q\z*.5j.
F];"d0O#5
%w+"MkH _
public Utility() <gvuCydsh
{ *C/bf)w
Gjhpi5?%8
yQAW\0`
} &J>XKO nl
Un[olp
//线程睡眠 m2%OX"#e
public static void sleep(int nSecond) ['<Q402:.
{ M]FA y"E
try{ ]i$<<u
Thread.sleep(nSecond); xEW>7}+\
} v[k;R
catch(Exception e) O!uZykdX4!
{ MK"p~b0->
e.printStackTrace (); 9'1XZpM1
} MR=dQc
} M)m(
z|KQiLza
//日志 Ptt
public static void log(String sMsg) $&fP%p
{ 7T\LYDT
System.err.println(sMsg); f*Z8C9)
} `S`,H
0m3:!#\
3pzp6o2
public static void log(int sMsg) @fI1|v=eF
{ eo#2n8I>=1
System.err.println(sMsg); Q7 4Q|r7
} _*K=Z,a;\
} 4q9+a7@
(]_smsok
xE$>;30b_
/* ILN Yh3
**TestMethod.java O V"5:){
*/ ";kwh8wB
package NetFox; =3~5I&
"b~-`ni
VnjhEEM!
public class TestMethod { i1c z+}
4!vovt{
"c9T4=]&t
public TestMethod() sYfiC`9SO
{ ///xx/weblogic60b2_win.exe iBqxz:PHN(
try{ ??]b,f4CNa
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q0m>NA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bZ5cKQ\6
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8|cQW-L
fileFetch.start(); qS9z0HLE
} Ii.0Bul
catch(Exception e){e.printStackTrace ();} |8{c|Qz
,(;TV_@$
Hf$pwfGcY]
} tM:%{az
su}n3NsJ
C:9a$
public static void main(String[] args) C j4ED
{ \yE*nZ
new TestMethod(); =Hd+KvA
} l-gNJ=l+K
} -"CXBKHb
点击下载更多相关资料