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)); VL2ACv(
} [t"#4[
for(int i=0;i<nEndPos.length-1;i++) S<>u
{ :s#&nY
nEndPos = nStartPos[i+1]; iJzW3%E
} 9`G}GU]@}
nEndPos[nEndPos.length-1] = nFileLength; w"OeS;#e:
} 1G 63eH)!
} YiC_,8A~
A2"$B\j1
Jqqt@5Ni
//启动子线程 yD(v_J*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g&d tOjM
for(int i=0;i<nStartPos.length;i++) @.l?V6g9T
{ ,e+S7YX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J#Agk^Y 5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (z^987G
nStartPos,nEndPos,i); 7jYW3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gkld}t*U
fileSplitterFetch.start(); kx07Ium
} ya'OI P `
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v}&J*}_XZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9`5qVM1O{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5Cl;h^R|m
nEndPos = " + nFileLength); RaAvPIJa |
// fileSplitterFetch[nPos.length-1].start(); N>',[4pJ|
?o_D#gG*
eG%Q 3h
//等待子线程结束 *"sDsXo- I
//int count = 0; G$CI~0Se:
//是否结束while循环 FoGSCg%
boolean breakWhile = false; 9pq-"?vHY0
P*{*^DN
R2dCp|6A
while(!bStop) t"FB}%G
{ [+>cW0a
write_nPos(); w[s}#Q
Utility.sleep(500); O"f|gc)GLz
breakWhile = true; 7A4_b8
>l(|c9OWM
W3Dtt-)E
for(int i=0;i<nStartPos.length;i++) Q5/BEUkC
{ dS~#Lzm
if(!fileSplitterFetch.bDownOver) ]B9Ut&mF;
{ nVv=smVOt
breakWhile = false; rWxQ;bb#
break; ^Mi&2AvS
} o :_'R5
} R^tDL
if(breakWhile) ^.(i!BG'
break; KcF#c_f
W,p?}KiO T
bs\7 juHt
//count++; av4g/7=
//if(count>4) 7N I~47s|v
// siteStop(); [E4#|w
} ("ulL5
-`} d@x
0v'FE35~s
System.err.println("文件下载结束！"); Zh3hCxXa
} Q*l_QnfG
catch(Exception e){e.printStackTrace ();} D?}K|z LQ
} sboX<
mybvD
3Fl!pq]
//获得文件长度 }^}ep2^
public long getFileSize() A]q"+Z]
{ +6+!M_0wA
int nFileLength = -1; &kNJs{
try{ I,wgu:}P#
URL url = new URL(siteInfoBean.getSSiteURL()); >Mc,c(CvU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :igURr
httpConnection.setRequestProperty("User-Agent","NetFox"); ^Yu%JCN8g
y759S)U>>p
O'~;|-Z<
int responseCode=httpConnection.getResponseCode(); ecG,[1];
if(responseCode>=400) `]3A#y)v
{ D+xHTQNTL
processErrorCode(responseCode); sQ>L3F;A`
return -2; //-2 represent access is error $l<(*,,l
} \oc*
@h";gN
n*vzp?+Y
String sHeader; IW-lC{hK
yp.\KLq8)
ibIo1i//[
for(int i=1;;i++) qZ|>{^a*
{ GI$7uR}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *='J>z.]
//Utility.log(in.readLine()); yPhTCr5pK
sHeader=httpConnection.getHeaderFieldKey(i); K|g+Wt^tQ
if(sHeader!=null) k x26nDT(
{ ,z+7rl
if(sHeader.equals("Content-Length")) fNTe_akp
{ I#U"DwM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zxffjz,Fe:
break; XAF*jevr
} (c=.?{U
} E+xC1U 3
else HbXYinG%
break; "hi)p9 _cR
} /a:sWmxMT
} sp'f>F2]
catch(IOException e){e.printStackTrace ();} d iGkwKj
catch(Exception e){e.printStackTrace ();} jdWA)N}kDG
8%W(",nd
1 /dy@'
Utility.log(nFileLength); "ABg,^jf
ir/-zp_
(^4V]N&
return nFileLength; heN?lmC
} 3}lT"K
:kz"Wya.
Q"2J2211
//保存下载信息（文件指针位置） 9pJk.Np0
private void write_nPos() _bm8m4Lk
{ E|K~WO]>o
try{ MhXJ /bup
output = new DataOutputStream(new FileOutputStream(tmpFile)); >azTAX6L3
output.writeInt(nStartPos.length); 8Z:T.Gc
for(int i=0;i<nStartPos.length;i++) 'ZboLoS*-
{ w%L::Z4
// output.writeLong(nPos); x%d\}%]
output.writeLong(fileSplitterFetch.nStartPos); XFv)]_G
output.writeLong(fileSplitterFetch.nEndPos); s}5,<|DL
} e0; KmQjG
output.close(); )ir*\<6Y=
} WQ>y;fi5/{
catch(IOException e){e.printStackTrace ();} U3UDA
catch(Exception e){e.printStackTrace ();} ?1kXV n$
} xYUC|c1Q9
8M&q
OPtFz6
//读取保存的下载信息（文件指针位置） YLVZ]fN=>
private void read_nPos() :G\X
{ K.T.?ug;:
try{ GjD^\d/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !:<(p
int nCount = input.readInt(); #Z)8,N
nStartPos = new long[nCount]; aUTXg60l*
nEndPos = new long[nCount]; ta'{S=^j
for(int i=0;i<nStartPos.length;i++) zs<2Ozv
{ d=v{3*a_4,
nStartPos = input.readLong(); =Mby;wQ?|
nEndPos = input.readLong(); /3`(Ki{ Q
} 8'}D/4MUr
input.close(); Svun RUE-f
} Ga M:/.
catch(IOException e){e.printStackTrace ();} R@[gkj
catch(Exception e){e.printStackTrace ();} .Fe_Z)i>h
} [W#M(`}D
:3aZ_
Q eZg l!
private void processErrorCode(int nErrorCode) S_ELV#X
{ \J0fr'(S
System.err.println("Error Code : " + nErrorCode); 9\J.AAk~/
} <<5x"W(,
LI`H,2Km
aR0'$*3E
//停止文件下载 M8p6f)l3
public void siteStop() Y;dQLZCC
{ Z| f~
bStop = true; '1r<g\l
for(int i=0;i<nStartPos.length;i++) +IkL=/';#
fileSplitterFetch.splitterStop(); )] C"r_
de<T5/
]b6gZ<
} }S_#*N)i
} KdTDBC
//负责部分文件的抓取 t<DZW#
**FileSplitterFetch.java (- QvlpZ
*/ 31> $;"
package NetFox; #vs=yR/tn{
dPmtU{E<M
e_v_y$
import java.io.*; xb22:
import java.net.*; ["65\GI?
Q]7}"B&
_Q=h3(ZI
public class FileSplitterFetch extends Thread { w$1B|7tX;2
Ht_7:5v&
li7"{+ct
String sURL; //File URL L7rH=gZ&!]
long nStartPos; //File Snippet Start Position &s>E~M0+J
long nEndPos; //File Snippet End Position ?Tr\r1s]
int nThreadID; //Thread's ID }VDJ
boolean bDownOver = false; //Downing is over 5xIOi(3`Q
boolean bStop = false; //Stop identical (ibj~g?U,
FileAccessI fileAccessI = null; //File Access interface ]r\d 5
6 #m:=
^2}p%j>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4Y `=`{Q
{ WLkfo6Nw
this.sURL = sURL; Hph$Z1{
this.nStartPos = nStart; k0^t$J W
this.nEndPos = nEnd; P3op1/Np
nThreadID = id; cf{rK`Ff^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 IQNvhl.{
} cI/Puh^3
r'E|6_0
8^2E77s4U
public void run() dZIruZ)x
{ X*QQVj
while(nStartPos < nEndPos && !bStop) g3Z"ri~!G
{ eX3|<Bf
3@8Zy:[8<
kl[Jt)"4@
try{ <#%kmYSL
URL url = new URL(sURL); 4E0 Y=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l37) Q
httpConnection.setRequestProperty("User-Agent","NetFox"); 5kdh!qy[$,
String sProperty = "bytes="+nStartPos+"-"; qw35LyL
httpConnection.setRequestProperty("RANGE",sProperty); tuIQiWHbM
Utility.log(sProperty); <#>{7" }
%Xjg/5G-
+txHj(Y`
InputStream input = httpConnection.getInputStream(); U%u%_{-
//logResponseHead(httpConnection); Fsi;[be$A
y??^[ sB
^"!)p2=
byte[] b = new byte[1024]; ;9"6g=q
int nRead; t=BXuFiu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :9Mqwgk,;3
{ -*AUCns#
nStartPos += fileAccessI.write(b,0,nRead); !'f.g|a
//if(nThreadID == 1) ,%4~ulKMn
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W)p?cK`
} <4,LTB]9-
sHn-#SGm
gl>%ADOB@
Utility.log("Thread " + nThreadID + " is over!"); ;{:bq`56f
bDownOver = true; [\,Jy8t)\
//nPos = fileAccessI.write (b,0,nRead); V \Sl->:
} YX{c06BHs
catch(Exception e){e.printStackTrace ();} #.W^7}H
} ?f&O4H
} gv}J"anD
/pYp,ak
%z"${ zw
//打印回应的头信息 SsfHp
public void logResponseHead(HttpURLConnection con) +5xk6RP
{ I6lWB(H!u
for(int i=1;;i++) n1r'Y;G
{ Gq0Q}[53
String header=con.getHeaderFieldKey(i); I|/\L|vo
if(header!=null) ;!Q}g19C
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kDWMget$
Utility.log(header+" : "+con.getHeaderField(header)); V PaW-o
else }+dDGFk
break; *9)yN[w
} !v68`l15
} (y!V0iy]
L7OFZ|gUz
kS1?%E,)q
public void splitterStop() rJw Ws
{ U])$#/ v
bStop = true; vHM,_I{
} s~n@|m9k
^udl&>
3u@=]0ZN
} 0$:jZ/._
(pT7m
y41,T&ja
/* 5Zy%Nam'gN
**FileAccess.java W+`T:Mgh
*//文件访问(定位，写) ~Hb2-V
package NetFox; L,_Z:\^
import java.io.*; $ )orXe|
)Nnrsa
HMl M!Xk?
public class FileAccessI implements Serializable{ &[qJ=HMm I
tr@)zM GB
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4"d'iY
RandomAccessFile oSavedFile; j:P(,M[
long nPos; @G?R(
9*;OHoDh
<Oihwr@5<
public FileAccessI() throws IOException I'e`?H t
{ %shCqS
this("",0); qj1Fj
} Ux+UcBKm-
9`T2
qLa6c2o,
public FileAccessI(String sName,long nPos) throws IOException 2f0qfF
{ HJ0Rcw%
oSavedFile = new RandomAccessFile(sName,"rw"); (Q F-=o
this.nPos = nPos; ':#DROe!
oSavedFile.seek(nPos); :)DvZxHE@
} ZIs=%6""&
Apbgm[m|{
RhD
public synchronized int write(byte[] b,int nStart,int nLen) z#Db~
{ |"i"8~/@<
int n = -1; 0@/C5 v
try{ rq![a};~
oSavedFile.write(b,nStart,nLen); 'tn-o
n = nLen; UoOxGo
} <RJ+f-
catch(IOException e) (,;4f7\
{ /j"aOLL|
e.printStackTrace (); x9i^_3Z
} TxvvCV^
>B$J
s7"5NU-
return n; s}g3*_"
} tf4clzSTa
]:}x 4O#
6oy[0hj
} /0(c-Dv
BNq6dz$J
5Mz6/&`
/* vEC#W43l
**SiteInfoBean.java .Zm de*b
*/ *^i"q\n5(
package NetFox; 1HBWOV7z.?
bEB9J- Q
W-<`Vo'
public class SiteInfoBean { (o518fmR
+6Ye'IOG
9"cyZO
private String sSiteURL; //Site's URL a Juv{
private String sFilePath; //Saved File's Path @Zw[LIQ*
private String sFileName; //Saved File's Name mu$rG3M
private int nSplitter; //Count of Splited Downloading File fR#W#n#m
6wH:jd9,
U$Od)
public SiteInfoBean() rp,Us#>6
{//nSplitter的缺省值为5 NuR3]Ja\0
//default value of nSplitter is 5 tOxTiaa=
this("","","",5); 04#<qd&ob@
} Tl L\&n.$
j|%>NB ):
3,)[Q?nKD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *QA{xvT
{ ~ugH2jiB
sSiteURL= sURL; Y lhKP;
sFilePath = sPath; bA\(oD+:
sFileName = sName; xwa@h}\#
this.nSplitter = nSpiltter; W<T Ui51Y
(kL(:P/
rAh|r}R
} ,*Wp$
[7h/ 2La#
l`rO)7
public String getSSiteURL() .s\_H,
{ J6gn!
return sSiteURL; B_S))3
} V0!kvIv
`Ln1g@
JQ9+kZ
public void setSSiteURL(String value) TTD#ovo'
{ w}0rDWuR[
sSiteURL = value; @nOuFX4
} ?G 'sb}.
N*SUA4bnuM
Zx^R-9
public String getSFilePath() gdkHaLL"
{ A@jBn6
return sFilePath; #@m6ag.
} J+l#!gk$!
&Xh=bM'/%m
uTNy{RBD+
public void setSFilePath(String value) uoTc c|Kc
{ A9y@v{txN
sFilePath = value; ]sJjV A
} Uj^Y\w-@Z
j+[oZfH
5h6-aQU[
public String getSFileName() T[kS;-x
{ &"DD&87N%
return sFileName; {Zo*FZcaX
} B/dJj#
9qm'qx
"rHPcp"m
public void setSFileName(String value) $ZlzS`XF7
{ th}&|Y)T2
sFileName = value; 8=u88?Bh
} 2/ejU,S
|y&vMx~t
y\Wp}}
public int getNSplitter() .t.4y. 97
{ ='6@^6y
return nSplitter; p~OX1RBI
} ?dmwz4k0
n^` `)"
Y8for'
public void setNSplitter(int nCount) ,qj M1xkL$
{ T;v^BVn
nSplitter = nCount; Se|h]+G
} |8fdhqy_
} HG^~7oMf
LBIEG_/m
4iY <7l8
/* Rp !Rzl<
**Utility.java lL&p?MUp
*/ <7o@7r'0
package NetFox; WS"v"J%
,{d=<j_
?ZYj5[op,H
public class Utility { p+V::O&&r
\O)u' Bu
oI"gQFGu`u
public Utility() f!G%$?]
{ vy5I#q(k
g{JH5IZ~
[6)vD@
} V o%GO9b;
= Q"(9[Az
//线程睡眠 U["IXR#
public static void sleep(int nSecond) j.:f=`xf
{ 64D4*GQ
try{ pp()Hu3J
Thread.sleep(nSecond); wrVR[v>E<
} syk,e4:oA
catch(Exception e) JqtOoR
{ 4F+G;'JV
e.printStackTrace (); i}@5<&J
} =Ds&ArG
} FYH^axpp
JC9OL.Ob
//日志 [Vj|fy4
public static void log(String sMsg) SDO~g~NTp
{ OT#foP
System.err.println(sMsg); mV}eMw
} L08"8\
n6{nx[%7N7
BRtT 7
public static void log(int sMsg) xLw[ aYy4
{ eNrwkV^
System.err.println(sMsg); c+jnQM'
} i}>}%l|
} Oyp)Wm;@
}3R:7N`,|
be'&tsZ9
/* $it>*%
**TestMethod.java gXB&Sgjo
*/ yn04[PN2
package NetFox; jR{t=da
iBCIJ!;
EHm:&w
public class TestMethod { ;(IAhWE?7
t}gK)"g
u HXb=U
public TestMethod() 6e;8\1^
{ ///xx/weblogic60b2_win.exe -;$jo-
try{ ~HXZ-*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); sVP2$?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); CN7qqd
SiteFileFetch fileFetch = new SiteFileFetch(bean); S.^x)5/,,T
fileFetch.start(); uU1q?|4
} BF U#FE)s
catch(Exception e){e.printStackTrace ();} >2tosxH M
3,Bm"'b6
_? u} Jy_
} `;&=m, W'
=%wBC;
l6!a?C[2T
public static void main(String[] args) r`C t/]c
{ XNkQ0o0
new TestMethod(); 7` t,
} ? \NT'CG
} E9j(%kQ2
点击下载更多相关资料