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)); a*qf\&Vb|
} Hn-k*Y/P
for(int i=0;i<nEndPos.length-1;i++) Po ,zTz
{ X;~3 U 9
nEndPos = nStartPos[i+1]; y<Z-f.
} gbC!>LV
nEndPos[nEndPos.length-1] = nFileLength; H{XD>q.
} D^G5$hi
} =GP~h*5es
NoR=:Q 9e
xE[CNJ%t^,
//启动子线程 @(~m.p|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _ ?\4k{ET
for(int i=0;i<nStartPos.length;i++) O%>FKU>(?
{ R*DQm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PB W.nm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), B9Ha6kj
nStartPos,nEndPos,i); *c0\<BI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i uNBw]
fileSplitterFetch.start(); Ykt{]#
} 5S;|U&f|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AP2BND9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cAL*Md8+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "TLY:V
nEndPos = " + nFileLength); YFGQPg
// fileSplitterFetch[nPos.length-1].start(); SWrt4G
,X&(BQj h
T!iRg=<bz
//等待子线程结束 snl$v
//int count = 0; 4X()D {uR
//是否结束while循环 %Ob#GA+
boolean breakWhile = false; MPn 6sf9M
pejG%pJ
m^9[k,;K
while(!bStop) [pc6!qhDG&
{ U#7moS'r
write_nPos(); hDP&~Mk
Utility.sleep(500); ?>\JX
breakWhile = true; A3!xYG=+
"I7 Sed7
OLl?1
for(int i=0;i<nStartPos.length;i++) No'^]r
{ aS7%x>.A!
if(!fileSplitterFetch.bDownOver) x+X^K_*
{ W=$cQ(x4Z
breakWhile = false; P+hp'YK1
break; #nzVgV]
} .Lvg $d
} <+/:}S4w)
if(breakWhile) /.Fvl;!J;
break; ,pg\5b
Uc?4!{$X
JyfWy
//count++; Xyf7sHQ
//if(count>4) PGj?`y4
// siteStop(); oD0N<Ln}
} #U=}Pv~wM
,o_Ur.UJ
Py3Y*YP
System.err.println("文件下载结束！"); ,)CRozC\}K
} 4;_<CB
catch(Exception e){e.printStackTrace ();} ToNRY<!
} h|DKD.
RyJN=;5p
PN +<C7/
//获得文件长度 fV\ eksBF
public long getFileSize() L, k\`9bQ
{ gOE3x^X*{
int nFileLength = -1; qXb{A*J
try{ xIrRFK9[Q
URL url = new URL(siteInfoBean.getSSiteURL()); 8%Wg;:DZx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;`TSu5/
httpConnection.setRequestProperty("User-Agent","NetFox"); 3 E~d
3XOf-v:~
L'*P;z7<
int responseCode=httpConnection.getResponseCode(); l$:.bwXXO
if(responseCode>=400) h /.^iT
{ 5z$>M3
processErrorCode(responseCode); %U4w@jp
return -2; //-2 represent access is error rLy<3
} 7n_'2qY
N@z+h
T9N&Nh7 3
String sHeader; ,IODV`L
IO(Y_7
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for(int i=1;;i++) s[ CnJZ\q
{ UT^-!L LB]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); AIx,c1G]K
//Utility.log(in.readLine()); g#=~A&4q
sHeader=httpConnection.getHeaderFieldKey(i); S!u`V3-s
if(sHeader!=null) KyqFeR
{ +&T;jad2
if(sHeader.equals("Content-Length")) X+:>&&9
{ `D#3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 77:s=)
break; TC2gl[
} vbZGs7%
} 5_d=~whO&2
else F$;vPAxbK"
break; uMB|x,X I
} xEA%UFB.!G
} ]{[8$|Mg
catch(IOException e){e.printStackTrace ();} ?^# h|aUp.
catch(Exception e){e.printStackTrace ();} dZ kr#>
e>ZF? (a0
{O"?_6',
Utility.log(nFileLength); NWGSUUa
/f:)I.FUm
]/_GHG9
return nFileLength; Hko(@z
} g;>M{)A
%o~w
2WA =U]
//保存下载信息（文件指针位置） /eoS$q
private void write_nPos() #2F 6}
{ OfR\8hAY
try{ ""dX4^gtU
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~+y0UEtq7
output.writeInt(nStartPos.length); $S"QyAH~-a
for(int i=0;i<nStartPos.length;i++) Vs)%*1><
{ f>u{e~Q,
// output.writeLong(nPos); 7Y8B \B)w
output.writeLong(fileSplitterFetch.nStartPos); owA0I'|V-A
output.writeLong(fileSplitterFetch.nEndPos); {GaQV-t
} is3nLm(
output.close(); %PsDS
} QSn%~o05
catch(IOException e){e.printStackTrace ();} 4E Hb
catch(Exception e){e.printStackTrace ();} NjTVinz
} sH^?v0^a
h-XMr_F
wGqQR)a
//读取保存的下载信息（文件指针位置） A0NNB%4|/
private void read_nPos() tGKIJ`w*h
{ jJpSn[{
try{ r "^{?0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I92c!`{
int nCount = input.readInt(); =,aWO7Pz
nStartPos = new long[nCount]; ~dIb>[7wy
nEndPos = new long[nCount]; 5 i1T?
for(int i=0;i<nStartPos.length;i++) !~'\Ey
{ Kb_R "b3v
nStartPos = input.readLong(); gc'C"(TO(
nEndPos = input.readLong(); &M)S~Hb^
} "CEy r0h
input.close(); }T?MWcG4
} XsldbN^6
catch(IOException e){e.printStackTrace ();} ~IHjj1s
catch(Exception e){e.printStackTrace ();} ^J8sR4p#
} ^6?NYHMr=
(1bz.N8z
>`jsUeS
private void processErrorCode(int nErrorCode) Oc;/'d2
{ ?kICYtY:_b
System.err.println("Error Code : " + nErrorCode); pai>6p
} ."m6zq
-%XvWZvZ
23/!k}G"
//停止文件下载 dVDQ^O&
public void siteStop() 9<An^lLK*
{ /`iBv8!
bStop = true; O<R6^0B42
for(int i=0;i<nStartPos.length;i++) xM1>kbo|
fileSplitterFetch.splitterStop(); tQ7DdVdix
h(,SAY_
hT&,5zaWdv
} (D'Z4Y
} 5zlgmCGow
//负责部分文件的抓取 guC/eSxv
**FileSplitterFetch.java i^{.Q-
*/ c<V.\y0x
package NetFox; r<;bArs-u
UarU.~Uqi
^n@.
import java.io.*; p}KZ#"Q
import java.net.*; $'f<4
bQ-5uFe~$B
}b9#.H9
public class FileSplitterFetch extends Thread { @:@0}]%z9
,L+tm>I
oZO6J-ea
String sURL; //File URL /EUv=89{!
long nStartPos; //File Snippet Start Position eNlE]W,=
long nEndPos; //File Snippet End Position Sti)YCXH
int nThreadID; //Thread's ID yQ4]LyS
boolean bDownOver = false; //Downing is over K\&A}R
boolean bStop = false; //Stop identical <zN
FileAccessI fileAccessI = null; //File Access interface S;$@?vF
9.|+KIRb
uQN8/Gy*J
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 47_4`rzy;
{ dbkccO}WB
this.sURL = sURL; e~r%8.Wm
this.nStartPos = nStart; 5_+vjV;5
this.nEndPos = nEnd; -OpI,qyS
nThreadID = id; 4#uWj?u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 PsDks3cG
} ?)#dP8n
?lv{;4BC
&\][:kG;
public void run() a z 7Vy-
{ UXvk5t1
while(nStartPos < nEndPos && !bStop) 09"C&X~
{ e{/(NtKf
w>T1D
eI?<*
try{ ^*C+^l&J!
URL url = new URL(sURL); b .k J&c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 65VnH=
httpConnection.setRequestProperty("User-Agent","NetFox"); *LeFI%
String sProperty = "bytes="+nStartPos+"-"; c/ wzV
httpConnection.setRequestProperty("RANGE",sProperty); >Dpz0v
Utility.log(sProperty); A)En25,X
]RmQ*F-
-6MgC9]
InputStream input = httpConnection.getInputStream(); yy4QY%
//logResponseHead(httpConnection); ?7@Y=7BS4
:g3n [7wR
]Ff"o7gT
byte[] b = new byte[1024]; <ns[( Q
int nRead; vq*N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \)VV6'zih
{ p_Fc:%j>
nStartPos += fileAccessI.write(b,0,nRead); 2O {@W +Mt
//if(nThreadID == 1) @FL?,_,Y{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %4U;Rdq&Ud
} hS&,Gm`^
L)VEA8}
)((Jnm D
Utility.log("Thread " + nThreadID + " is over!"); 2%N$Y]
bDownOver = true; nBL7LocvR
//nPos = fileAccessI.write (b,0,nRead); ~C< X~$y&
} @L^2VVWk^
catch(Exception e){e.printStackTrace ();} \t'(&taX<
} IpY R
} s z/7cLo
JwbC3t):@
Nm%&xm
//打印回应的头信息 |@={:gRJ{x
public void logResponseHead(HttpURLConnection con) -UkP{x)S
{ 6%NX|4_
for(int i=1;;i++) >`p`^:
{ )JE;#m0q
String header=con.getHeaderFieldKey(i); aksyr$d0V<
if(header!=null) C$\|eC j
//responseHeaders.put(header,httpConnection.getHeaderField(header)); sTdD=>
Utility.log(header+" : "+con.getHeaderField(header)); jcQ{,9 H`l
else R-J\c+C>W
break; pt;E~_
} VO>A+vx3M
} 8qn1?Lb
$<2r;'?0D
%\=5,9A\
public void splitterStop() 8Cz_LyL
{ xh[Mmq/R
bStop = true; HDYr?t~V
} CfQOG7e@
*. l,_68
O^hWG ~o
} 4H8vB^
AD=@
/j./
/* {gluK#Qm
**FileAccess.java Dna0M0
*//文件访问(定位，写) $"C]y$}
package NetFox; bLGgu#
import java.io.*; r#*kx#"
/ZZo`
,Cj1S7GFR
public class FileAccessI implements Serializable{ /K2VSj3\
tYiK#N7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 w"$CV@AJ
RandomAccessFile oSavedFile; R6]/g
long nPos; ,xB&{J
d7qY(!&
,K .P,z~*
public FileAccessI() throws IOException Ojq>4=Z\
{ uQWJ7Xm
this("",0); R_\{a*lV0
} vb)Z&V6(
EsXCi2]1
EP&iG%(k
public FileAccessI(String sName,long nPos) throws IOException KZzOs9 s
{ }rsD$
oSavedFile = new RandomAccessFile(sName,"rw"); x)l}d3
this.nPos = nPos; g}0}$WgH:
oSavedFile.seek(nPos); !!4_x
} dON4r2-yC
qI\qpWS\
oL>m}T
public synchronized int write(byte[] b,int nStart,int nLen) br+{23&1R#
{ 'YQ"Lf
int n = -1; {NXc<0a(
try{ 6ND,4'6
oSavedFile.write(b,nStart,nLen); 7kO5hlKeo
n = nLen; -}1S6dzr
} ;$l!mv7
catch(IOException e) XP *pYN
{ Q^/66"Z:Z
e.printStackTrace (); CFAz/x@%
} G+ PBV%gE[
2]C`S,)
m `~/]QQ
return n; |/C>xunzz
} -}@3,G
1HL}tG?+#
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} Sx+.<]t2A
L.>tJ.ID
F=yrqRS=
/* *DObtS_ 6
**SiteInfoBean.java P!'Sx;C^f
*/ kM|akG
package NetFox; AJ`b-$Q
HS.3PE0^C
NmYSk6kWJ
public class SiteInfoBean { rc1EJ(c
Um]>B`."wK
u&?J+
private String sSiteURL; //Site's URL QgO@oV*S
private String sFilePath; //Saved File's Path JYOyz+wNd
private String sFileName; //Saved File's Name S*Un$ngAh
private int nSplitter; //Count of Splited Downloading File yd[}?
D{I^_~-\5
lidzs<W-fW
public SiteInfoBean() RxU6.5N
{//nSplitter的缺省值为5 YFOSv]w
//default value of nSplitter is 5 _C~e(/=z
this("","","",5); 2;r(?ebw
} n?_!gqK
hL~@Ah5&t
Ke,UwYG2~G
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o)Kx:l +f
{ \ F#mwl,>"
sSiteURL= sURL; Q\&FuU
sFilePath = sPath; =_I2ek
sFileName = sName; %/b?T]{
this.nSplitter = nSpiltter; frbKi _1
ZXljCiNn+\
A U9Y0<
} GLQ1rT
JDfkm+}uY
G$XvxJ
public String getSSiteURL() ~V[pu
{ %sP C3L
return sSiteURL; )+RTA y[k
} 1O*5>dkX;%
YpoO:
b>=MG8
public void setSSiteURL(String value) ^'!]|^
{ .x5Yfe
sSiteURL = value; hH[UIe
} xK9"t;!C&
uS<7X7|!0
=z'- B~
public String getSFilePath() _HX1E
{ Z0g3> iItM
return sFilePath; ]N_(M
} f1(V~{N,+
5p}Y6Lc\j
v~e@:7d i
public void setSFilePath(String value) j*nZ
{ 8PB(<|}u
sFilePath = value; f@l$52f3D
} z(d@!Cd
>J^bs &j
0? (
public String getSFileName() >[B}eS>
{ ZQ9!k* ^
return sFileName; V|KYkEl r1
} vBx*bZ
JO\Tf."a\
n3t1'_/TU}
public void setSFileName(String value) [H)NkR;I
{ v]\io#
sFileName = value; eyf\j,xP&
} iM+K&\{_h
)$Xd#bzD|
A9\m.3jo
public int getNSplitter() Y,?s-AB
{ ,S E5W2a]
return nSplitter; ]\w0u7}
} "- S2${
X>:@`}bq
#XR<}OYcL
public void setNSplitter(int nCount) GY,l&.&
{ w~+5FSdH
nSplitter = nCount; T#xCu|5
} k v1q\
} azR<Y_tw
md:$OC3
Y~EKMowI&e
/* {i y[8eLg
**Utility.java 3XdN\xc
*/ @-nCK Yj
package NetFox; Yh)yp?
S/G6NBnbS
4zs1BiMG
public class Utility { x*& OvI/o
H$TYp
0KO_bF#EB=
public Utility() *c4uCI:0t
{ gQ4Q h;
HMGby2^+
8aZuI|z
} i <0H W
|@?B%sY
//线程睡眠 |&B.YLx
public static void sleep(int nSecond) \9;u.&$mNB
{ LWE[]1=
try{ bg;NBoZd
Thread.sleep(nSecond); FJKW=1=,
} g3Q]W(F%$
catch(Exception e) X{zg-k(@
{ (e sTb,
e.printStackTrace (); HKr")K%
} im{'PgiR
} ON#\W>MK?
|3{DlZ2S
//日志 j_S///
public static void log(String sMsg) rOQhS]TP*
{ >ch{u{i6
System.err.println(sMsg); v9R#=m/=
} Fq/?0B8
wEL$QOu$
+^tq?PfE
public static void log(int sMsg) YY-{&+,
{ nD6mLNi%a
System.err.println(sMsg); CY;ML6c@
} d2lOx|jt
} 4<._)_m
oR (hL4Dc
RaT(^b(
/* n B4)%
**TestMethod.java Y,EReamp
*/ dd1m~Gm
package NetFox; n^P=a'+
\hN\px
dK'?<w$
public class TestMethod { V&`\ s5Q
RN\4y{@
x)0g31 49
public TestMethod() 9t@^P^}=\m
{ ///xx/weblogic60b2_win.exe ?hUC#{
try{ TxAT ))
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &os9K)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 92_F8y*D
SiteFileFetch fileFetch = new SiteFileFetch(bean); # D"TY-$.=
fileFetch.start(); <"w;:Zs
} V\^rs41$;
catch(Exception e){e.printStackTrace ();} /.<%y8v
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e^kccz2f
} Qj: D=j8
'7G'R
<,p|3p3
public static void main(String[] args) *O-1zIlp
{ bOjvrg;Sz\
new TestMethod(); Poy ]5:.
} fP>_P#gZ
} 0VC8'6S_k
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