http断点续传简单实现（java)

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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)); [2Ot=t6]
} D;QV`Z%I
for(int i=0;i<nEndPos.length-1;i++) v!77dj 6I
{ 85 <%L:EC
nEndPos = nStartPos[i+1]; /Ym!%11`
} >P[BwL]
nEndPos[nEndPos.length-1] = nFileLength; :1,xse
} wS}Rl}#Oh?
} =?s0.(;
8PtX@s43\
c!HmZ]/
//启动子线程 $mLiEsJ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v7@O ,%
for(int i=0;i<nStartPos.length;i++) =VOl *
{ c?XqSK`',Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0|D l/1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e=Teq~K
nStartPos,nEndPos,i); $ Ov#^wfA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %^ g(2^
fileSplitterFetch.start(); ; 6*Ag#Z
} CyEEE2cV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TATH,Sz:x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FErKr)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3E]IEf
nEndPos = " + nFileLength); $G@^!(
// fileSplitterFetch[nPos.length-1].start(); 71inHg
"R9^X3;
{u_2L_
//等待子线程结束 19#A7
//int count = 0; HC\\w-`<
//是否结束while循环 k}$k6Sr"
boolean breakWhile = false; l5fF.A7TT
nk^-+olm
bdz&"\$X
while(!bStop) ~u+|NtF
{ ^#)M,.G^
write_nPos(); EaXDY<
Utility.sleep(500); ug.'OR
breakWhile = true; os~}5QJ
KM jnY2
)'Yoii{dSU
for(int i=0;i<nStartPos.length;i++) IWD21lS
{ %2t#>}If!
if(!fileSplitterFetch.bDownOver) 2i_X{!0}
{ vhj^R5=
breakWhile = false; oq3{q
break; Ad]oM]
} k}r)I.Lp
} 9HJA:k*k|
if(breakWhile) 8w]>SEGFs
break; g{%2*{;i
_rjLCvv-
O| zLD
//count++; /aHx'TG
//if(count>4) h&$,mbEoI
// siteStop(); wc7F45l4
} *zn=l+c
<=7N2t)s4
K`% I!Br
System.err.println("文件下载结束！"); @!zT+W&
} cA]Ch>]A%
catch(Exception e){e.printStackTrace ();} wc6v:,&
} Pu7cL
At=l>
2W]y9)<c
//获得文件长度 qtLXdSc
public long getFileSize() jYi{[**
{ iJD_qhd7
int nFileLength = -1; }j /r
try{ Q($aN-
URL url = new URL(siteInfoBean.getSSiteURL()); 2lm{:tS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *N|s+
httpConnection.setRequestProperty("User-Agent","NetFox"); y/}ENUGR
{pof=G
y$^.HI02jP
int responseCode=httpConnection.getResponseCode(); b/g"ws_
if(responseCode>=400) l5bd);Ltq
{ ^vH3 -A;*
processErrorCode(responseCode); ? (f44Zgm
return -2; //-2 represent access is error j*05!j<'
} 8NS1*\z
v'zj<|2
`GD>3-
String sHeader; WCPl}7>
aA/.EAc7
wBK%=7
for(int i=1;;i++) L_4ZxsIv
{ m&X6a C'[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oI6o$C
//Utility.log(in.readLine()); gQ=g,X4
sHeader=httpConnection.getHeaderFieldKey(i); QC\][I>
if(sHeader!=null) zkrcsc\Z~0
{ E?+MM0
if(sHeader.equals("Content-Length")) Q]]5\C.
{ &QQ8ut,;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ; 3WA-nn
break; &^W91C?<6
} \dIQhF%%2
} r$Z_Kwe.|&
else _^)<d$R<
break; 6Wabw:
} E-_Q3^
} /kY|PY
catch(IOException e){e.printStackTrace ();} @^';[P!
catch(Exception e){e.printStackTrace ();} 3_]<H<w
k)a-odNrb
L--(Y+vmf
Utility.log(nFileLength); s s*% 3<
l[EjtN
MXj7Z3
return nFileLength; rHWlv\+Nn
} pwvcH3l/r
'~ {xn
Lz9t9AoB
//保存下载信息（文件指针位置） Q< q&a8~
private void write_nPos() "x*5g*k
{ 5z>kz/uxW
try{ k'K&GF1B
output = new DataOutputStream(new FileOutputStream(tmpFile)); '`*{ig
output.writeInt(nStartPos.length); Pkbx/\
for(int i=0;i<nStartPos.length;i++) oe:@7stG
{ @!:~gQ
// output.writeLong(nPos); l`vb
output.writeLong(fileSplitterFetch.nStartPos); De(\<H#
output.writeLong(fileSplitterFetch.nEndPos); Hi 1@
} E\(dyq/
output.close(); jB17]OCN
} =k1 ,jn+
catch(IOException e){e.printStackTrace ();} d,G:+
catch(Exception e){e.printStackTrace ();} vNhi5EU
} <?UIux
KnC;j-j
/@<Pn&Rq
//读取保存的下载信息（文件指针位置） z3 lZ3
private void read_nPos() L]goHs
{ Qw ukhD7
try{ &O'6va
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gqje]Zc<
int nCount = input.readInt(); lKMOsr@l
nStartPos = new long[nCount]; y0d a8sd)
nEndPos = new long[nCount]; E2s lpo
for(int i=0;i<nStartPos.length;i++) ]mN'Qoc
{ 5;5DEMe
nStartPos = input.readLong(); ]i-peBxw
nEndPos = input.readLong(); `;ofQz4
} rSUarfZ<
input.close(); GN4'LU
} 3f2%+2Zjt,
catch(IOException e){e.printStackTrace ();} A?V[/
catch(Exception e){e.printStackTrace ();} ERO'{nT&
} swBgV,;
:3s5{s
>Q$, } `U;
private void processErrorCode(int nErrorCode) 4E`y*Hmzy+
{ 3Ms` ajJ
System.err.println("Error Code : " + nErrorCode); +ou ]|
} xm}9(EJ
b3G4cO;t;
iINd*eXb^
//停止文件下载 Ny@CP}
public void siteStop() I6x
{ HWJ(O/N
bStop = true; lw4#xH-?
for(int i=0;i<nStartPos.length;i++) fWx %?J
fileSplitterFetch.splitterStop(); CfguL@tR.
:esHtkyML
d;3/Vr$t=
} 6q[|U_3I@
} BitP?6KX
//负责部分文件的抓取 B&~#.<23:
**FileSplitterFetch.java R\%&Q|
*/ 2nW:|*:/p6
package NetFox; 3[g%T2&[
S <C'#vj
o~#cpU4{o
import java.io.*; d%:B,bck
import java.net.*; 2NHkK_B1P
M^c`j#NQ
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public class FileSplitterFetch extends Thread { g]IRv(gDh
v=A]#O%
'~HCYE:5
String sURL; //File URL 7~@9=e8G
long nStartPos; //File Snippet Start Position #V[j Q Vl
long nEndPos; //File Snippet End Position d{cd+An
int nThreadID; //Thread's ID Bb5|+bP
boolean bDownOver = false; //Downing is over t6GL/M4
boolean bStop = false; //Stop identical )[d?&GK
FileAccessI fileAccessI = null; //File Access interface gOpi>
v+. n9
/;7\HZ$@/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'D ,efTq
{ d NQ?8P-&
this.sURL = sURL; Yj/aa0Ka4
this.nStartPos = nStart; *=Ko"v }
this.nEndPos = nEnd; %#xdD2oN
nThreadID = id; {sn RS)-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /gkHV3}fu
} e>zCzKK
EZy:_xjZ
AJ_''%$I3:
public void run() F?UI8
{ Arg604V3
while(nStartPos < nEndPos && !bStop) ~)\9f 1O{^
{ A"(XrL-pV
9yU(ei:GUo
:6k8\{^9"D
try{ `mar-r_m
URL url = new URL(sURL); <L4.*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^I=W<
httpConnection.setRequestProperty("User-Agent","NetFox"); ;D}8acQ
String sProperty = "bytes="+nStartPos+"-"; {MP8B'r-6
httpConnection.setRequestProperty("RANGE",sProperty); lSGtbSyDI
Utility.log(sProperty); toDv~v
3uSj5+@q6
E8_j?X1
InputStream input = httpConnection.getInputStream(); kD&% 7Vz
//logResponseHead(httpConnection); ^P4q6BW
,/?7sHK-0
Y>Oh]?
byte[] b = new byte[1024]; K4\{G
int nRead; rI/;L<c
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~#z8Q{!O
{ b@GL*Z
nStartPos += fileAccessI.write(b,0,nRead); Af~>}-`a
//if(nThreadID == 1) ObK-<kGcB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]mDsd*1
} {+`'ZU6C
vL>cYbJ<
V}?*kx~T2C
Utility.log("Thread " + nThreadID + " is over!"); +m|S7yr'
bDownOver = true; ^|u7+b'|t
//nPos = fileAccessI.write (b,0,nRead); 8|Wu8z--
} d']CBoK
catch(Exception e){e.printStackTrace ();} <>=A6
} }e/#dMEi
} v5 |XyN"
F#0y0|
mGss9eZa
//打印回应的头信息 ]!@z3Hv3
public void logResponseHead(HttpURLConnection con) 1r!o,0!d-'
{ M]FA y"E
for(int i=1;;i++) 6Z09)}tZb
{ :%_*C09
String header=con.getHeaderFieldKey(i); (u/-ud1p
if(header!=null) <ttrd%VW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'CF?pxNQ l
Utility.log(header+" : "+con.getHeaderField(header)); Y[_{tS#u
else <+7]EwVcn^
break; Ue:LKK1Gsr
} vBFMne1h
} y {&"g
M)m(
;iol 2
public void splitterStop() 29a~B<e7s
{ %pikt7,Z~
bStop = true; (8JL/S;Z$
} Lek!5Ug
7D5[ L
2O|jVGap5x
} f*Z8C9)
WruSL|4iH
UY(pKe>
/* 8IeE7
**FileAccess.java 49('pq?D
*//文件访问(定位，写) jN3K= MA
package NetFox; ^{<!pvT
import java.io.*; &c?q#-^)\+
XZh1/b^DMN
w^{qut.
public class FileAccessI implements Serializable{ h>w(Th\H
$-J0ou8~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x9DG87P~+
RandomAccessFile oSavedFile; rI'kGqU
long nPos; ^bD)Tg5K
*Z9Rl>
DGc5Lol~
public FileAccessI() throws IOException hSl6X3W
{ O V"5:){
this("",0); `;`fA|F^
} !6`pq
n]%T>\gw
5`_UIYcI
public FileAccessI(String sName,long nPos) throws IOException ''Pu
{ U4$}8~o4
oSavedFile = new RandomAccessFile(sName,"rw"); Jw+k=>
this.nPos = nPos; tv]^k]n{rf
oSavedFile.seek(nPos); (h8RthQt
} Ihn#GzM?u
=pT}]
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public synchronized int write(byte[] b,int nStart,int nLen) %qycxEVP
{ i?HN
int n = -1; {wp~
try{ +hIC N,8!
oSavedFile.write(b,nStart,nLen); eNHSfq
n = nLen; =<BPoGs5
} S9 p*rk~
catch(IOException e) ' ?4\
{ dmB _`R
e.printStackTrace (); KUV(vAY,
} ~ERA
&06pUp iS
G5oBe6\C
return n; Kggc9^ 7
} GJr1[
.!`y(N0hc
p2=+cS"HC
} kd=|Iip;(
h,*-V 'X.k
kB! iEoIBA
/* y/.I<5+Bu
**SiteInfoBean.java M#u~]?hS
*/ 0Tv0:c>8;(
package NetFox; ZZ? KD\S5
r|ID]}w
}J^+66{
public class SiteInfoBean { =Hd+KvA
K,f"Q<sU%
mNQ~9OJ1
private String sSiteURL; //Site's URL nb30<h
private String sFilePath; //Saved File's Path 0en Bq>vr
private String sFileName; //Saved File's Name _xmS$z)TO
private int nSplitter; //Count of Splited Downloading File i-YSt5iq
{<P{uH\l
b(HbwOt~3
public SiteInfoBean() K ; eR)
{//nSplitter的缺省值为5 Y00hc8<
//default value of nSplitter is 5 "y7IH GJ\3
this("","","",5); 4!U)a
} lf9mdbm
}m -A #4.
Lz/{ q6>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p Lwtm@
{ olxnQYFo
sSiteURL= sURL; FoW|BGA~
sFilePath = sPath; xbNL <3"a
sFileName = sName; <*3#nA-O>i
this.nSplitter = nSpiltter; )JXlPU
c}G\F$
=M],5<2;
} >(\Z-I&YQ
lc(}[Z/|V
Gl6M(<f\5
public String getSSiteURL() VBN=xg}
{ <hBd #J
return sSiteURL; bjr()NM1
} 4(%LG)a4S
~7$jW[i
4>NmJrh
public void setSSiteURL(String value) oXgi#(y
{ Koi-b
sSiteURL = value; s= bP@[Gj
} :\"V5
,Zva^5
O$(#gB'B
public String getSFilePath() d "%6S*dL
{ ]j+J^g
return sFilePath; ,382O$C
} 9YvK<i&I
<i ";5+
7?p>v34A
public void setSFilePath(String value) Vv_lBYV
{ >|rU*+I`
sFilePath = value; V'8Rz#Gc5
} }G ^nK m
*cy!PF&
1a tQ9
public String getSFileName() Zq"
{ &Vy.)0
return sFileName; ~F.kgX
} ZkqZO#nq C
Zv5vYe9Ow
XR+
public void setSFileName(String value) {lbNYjknS
{ ?_j]w%Hz
sFileName = value; 1xDh[:6
} q+U&lw|"w
!%(PN3*
Ya29t98Pk
public int getNSplitter() Jy P$'v~
{ >c=-uI
return nSplitter; D zdKBJT+
} K)#6&\0tT
%cl{J_}{&
B&"c:)1 C2
public void setNSplitter(int nCount) .W51Cup@&
{ ;$g?W"
nSplitter = nCount; 7_~_$I~g*
} x-s\0l
} 'Gqo{wl
4Cp)!Bq?/
M&}_3
/* f/670Acv
**Utility.java UgTgva>?
*/ OjurfVw
package NetFox; jk{m8YP)E
C#@-uo2
B)BR y%
public class Utility { |e91KmiqJ
Ge ?Q)N
+ctJV>
public Utility() w,-4A o2x
{ Sr>5V
U"535<mR
]92=PA>75
} ,0aRHy_^
/pL'G`
//线程睡眠 w3FEX$`_
public static void sleep(int nSecond) R,`3 SW()
{ ltlnXjRUv
try{ OWZ;X}x
Thread.sleep(nSecond); .RpWE.C
} w"q^8"j!
catch(Exception e) :_:o%
{ """pe+Y
e.printStackTrace (); KvumU>c#A
} N=j$~,yG
} NEt_UcC
W?yGV{#V(=
//日志 AWDy_11Nm
public static void log(String sMsg) @7J;}9E
{ yL_\&v
System.err.println(sMsg); M;sT+Z{
} J@qwz[d i
Xb.# =R
Vo%DoZg
public static void log(int sMsg) 5P[urOvV
{ dMK\ y4#i
System.err.println(sMsg); 1IN^,A]r2h
} )CD-cz6n
} )v %tyU
11B8 LX
g^))
/* Lj1>X2.gD
**TestMethod.java ]Cp`qayct
*/ ?:3rVfO
package NetFox; :'sMrf_EA
i2!0bY
GpCjoNcW{
public class TestMethod { w01u~"E
n9Ktn}
MPMAFs
public TestMethod() %:8XZf
{ ///xx/weblogic60b2_win.exe 3K%_wCZ
try{ 7)*QX,4C
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #zg"E<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .[o`TlG%
SiteFileFetch fileFetch = new SiteFileFetch(bean); yGC3B00Z
fileFetch.start(); $1n\jN
} $*C'{&2
catch(Exception e){e.printStackTrace ();} yc0_7Im?
%t%D|cf
`.F3&pA
} #@<L$"L
XhmUtbs
2U) 0k*
public static void main(String[] args) Nuaq{cl
{ V82hk0*j
new TestMethod(); (/C 8\}Ox
} AQ)J|i
} #0c;2}D
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