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)); X's<+hK&
} $)X8'1%6
for(int i=0;i<nEndPos.length-1;i++) ,LSiQmV5
{ [eOv fD
nEndPos = nStartPos[i+1]; Ok\X%avq
} < FO=PM
nEndPos[nEndPos.length-1] = nFileLength; vp*+Ckd
} "dDrw ]P;
} Gky^S#
lQ!OD&6
[Y@>,B!V
//启动子线程 :{lP9%J-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SA=>9L,2
for(int i=0;i<nStartPos.length;i++) YOrq)_ l
{ pz)>y&_o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xh9$ZavB*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %OO}0OW
nStartPos,nEndPos,i); RB%y($
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1^= QIX
fileSplitterFetch.start(); +DR$>a
} x{<l8vL=-c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NT5'U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fG$LqzyqlK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w=rD8@
nEndPos = " + nFileLength); Hk h'h"_r
// fileSplitterFetch[nPos.length-1].start(); hKWWN`;b !
zUv#%Q8vw
|Rhqi
//等待子线程结束 vPz7*w
//int count = 0; ,J!$Q0e
//是否结束while循环 r-.@MbBm
boolean breakWhile = false; 1TGRIe)
+FqE fY4j
zhFm2
while(!bStop) v*=P
{ A( vdlj
write_nPos(); +s"6[\H1d
Utility.sleep(500); A0k?$ko
breakWhile = true; H;=Fq+
"z3rH~q72
|llJ%JhF
for(int i=0;i<nStartPos.length;i++) 4m1r@ $
{ G--X)h-
if(!fileSplitterFetch.bDownOver) %>i:C-l8
{ ja';NIO-
breakWhile = false; tS]
break; TSsZzsdr2
} ZCPUNtOl
} L1/`/
if(breakWhile) Kmx^\vDs
break; A&~fw^HM
0C/ZcfFU~
oYStf5
//count++; RK|*yt"f"
//if(count>4) Hn(1_I%zF
// siteStop(); Ws@'2i\;
} |9c~kTjK
qVE0[ve
'!Hs"{~{
System.err.println("文件下载结束！"); 4r1\&sI$~
} &R_7]f+%)
catch(Exception e){e.printStackTrace ();} ~,HFd`
} @>(KEjQTz
Ytlzn%
)P:^A9&_n=
//获得文件长度 _q27 3QG/"
public long getFileSize() EaO@I.[
{ qMNWw\k
int nFileLength = -1; lZcNio
try{ LJ(WU)CPc
URL url = new URL(siteInfoBean.getSSiteURL()); nG!<wlY14P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8I#ir4z#<
httpConnection.setRequestProperty("User-Agent","NetFox"); 'cXdc
YNU}R/u6^
_]>1(8_N
int responseCode=httpConnection.getResponseCode(); sV
if(responseCode>=400) .Q*X5Fc
{ }#O!GG{
processErrorCode(responseCode); F`nQS&y
return -2; //-2 represent access is error ijF_ KP'
} hJ'H@L7
tF0jH+7J-
@0?!bua_|
String sHeader; \beO5]KS<
vjGQ!xF
7z{wYCw
for(int i=1;;i++) 7Gc{&hp*
{ fe?Z33V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .w9LJ
//Utility.log(in.readLine()); FM@iIlY"
sHeader=httpConnection.getHeaderFieldKey(i); Zh<;r;2
if(sHeader!=null) u]J@65~'b
{ pE4a~:
if(sHeader.equals("Content-Length")) I0)`tQ+
{ W_\zx<m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); fGo4&( U
break; k"(]V
} nVb@sI{{k
} BX@Iq
else Wy}I"q[~So
break; I &t~o
} x *eU~e_jP
} E $@W~).!
catch(IOException e){e.printStackTrace ();} }rTH<!j
catch(Exception e){e.printStackTrace ();} e#(Ck{e
~U9K<_U
*v>ZE6CL
Utility.log(nFileLength); tgK I
_kj]vbG^;
f!Q\M1t)
return nFileLength; !'7fOP-J]
} Jg6Lr~!i
BM%wZ: s
'rD6MY
//保存下载信息（文件指针位置） xt{'Be&Ya+
private void write_nPos() wl Oeoi
{ E$e7(D
try{ /Rp]"S vt
output = new DataOutputStream(new FileOutputStream(tmpFile)); C6_(j48&
output.writeInt(nStartPos.length); J3K=z
for(int i=0;i<nStartPos.length;i++) IV QH p
{ yBIlwN`kB
// output.writeLong(nPos); 'Wonz<{'
output.writeLong(fileSplitterFetch.nStartPos); ]T4/dk&|o^
output.writeLong(fileSplitterFetch.nEndPos); OZ,kz2SF#
} )?L=o0
output.close(); 5gszAvOO
} m7 =$*1k
catch(IOException e){e.printStackTrace ();} sGvbL-S-f:
catch(Exception e){e.printStackTrace ();} S2~cAhR|M
} J~Xv R
Kz4S6N c
!Brtao"m
//读取保存的下载信息（文件指针位置） WL$^B@gXQ
private void read_nPos() j=_rUc'Me
{ &J[a.:..
try{ X|M!Nt0'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); YeX*IZX8
int nCount = input.readInt(); +Q*`kg'
nStartPos = new long[nCount]; g;IlS*Ld
nEndPos = new long[nCount]; Y4T")
for(int i=0;i<nStartPos.length;i++) [\uR3$j#
{ 2EY"[xK|
nStartPos = input.readLong(); dn6B43w
nEndPos = input.readLong(); DA=U=F
} _`$LdqgE
input.close(); q>q:ZV
} <Ox[![SR
catch(IOException e){e.printStackTrace ();} yoi4w 7:
catch(Exception e){e.printStackTrace ();} &4'<{
} <G"cgN#]
E$d3+``
A=CeeC]}
private void processErrorCode(int nErrorCode) #F*|@
{ X@nBj;
System.err.println("Error Code : " + nErrorCode); 0r]n 0?x
} ><%585
+bjy#=
$o6/dEKQ
//停止文件下载 -H1=N
public void siteStop() B.<SC
{ T}~TW26v
bStop = true; Ku;fZN[g
for(int i=0;i<nStartPos.length;i++) gmTBT#{6yH
fileSplitterFetch.splitterStop(); .@dC]$2=
;'!x
&9k~\;x
} ;%|im?
} `i{d"H0E
//负责部分文件的抓取 ^Fk;t
**FileSplitterFetch.java }v(wjD
*/ c0Ug5Vr
package NetFox; ! VwU=5
PN}+LOD<t
sW^M ]
import java.io.*; 5<?Ah+1
import java.net.*; ?z ,!iK`
Z\$HgG
|9@,ri\'Rg
public class FileSplitterFetch extends Thread { +vc+9E.?9
n `j._G
9rB3h`AVF
String sURL; //File URL IQQv+af5
long nStartPos; //File Snippet Start Position D)*
long nEndPos; //File Snippet End Position [%IOB/{N
int nThreadID; //Thread's ID {1GJ,['qL
boolean bDownOver = false; //Downing is over sYTz6-
boolean bStop = false; //Stop identical NW|B|kc
FileAccessI fileAccessI = null; //File Access interface *MJm:
?2<QoS
Iil2R}1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @uSO~.7
{ ^[ae )}
this.sURL = sURL; +sNS
this.nStartPos = nStart; !_glZ*tL
this.nEndPos = nEnd; ;W|kc</R*
nThreadID = id; <J%qzt}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E4#{&sRT
} _K5<)( )
ZvY"yl?e
OjU{r N*
public void run() vrn4yHoZ
{ S)CsH1Q
while(nStartPos < nEndPos && !bStop) tX*@r
{ SH*'<
5!0iK9O
$-_" SWG.
try{ F`}'^>
URL url = new URL(sURL); Y A.&ap
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z:'m50'
httpConnection.setRequestProperty("User-Agent","NetFox"); wGHft`Z
String sProperty = "bytes="+nStartPos+"-"; G/x6zdk
httpConnection.setRequestProperty("RANGE",sProperty); ]#~J[uk
Utility.log(sProperty); KFM[caKeJO
g%2G=gR$?z
*0U#Z]t
InputStream input = httpConnection.getInputStream(); deVd87;@7[
//logResponseHead(httpConnection); 4^(x)r &(?
Ff<cY%t
]0i[=
byte[] b = new byte[1024]; mR}8}K]L
int nRead; &{)<Q(g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4S(G366
{ EeaJUK]z9
nStartPos += fileAccessI.write(b,0,nRead); /%YW[oY{V
//if(nThreadID == 1) nC:T0OJv
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "jZZ>\
} 4vg,g(qi<
8~y!X0Ov!
r*HSi.'21
Utility.log("Thread " + nThreadID + " is over!"); oKGH|iVEe
bDownOver = true; ?[Yn<|
//nPos = fileAccessI.write (b,0,nRead); @Y~gdK
} a$W O}g?
catch(Exception e){e.printStackTrace ();} <XL%*
} b~;:[ #
} 9FEhl~&
`n+uA~
F'~r?D
//打印回应的头信息 $$AZ)#t[
public void logResponseHead(HttpURLConnection con) % :G78.
{ 33`bKKO}
for(int i=1;;i++) VnuG^)S
{ eKP>}`
String header=con.getHeaderFieldKey(i); ;v8TT}R
if(header!=null) ~HY)$Yp;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `=Mk6$%Cs
Utility.log(header+" : "+con.getHeaderField(header)); HSud$(w
else x.t<@y~
break; dX\OP>
} ,]wab6sY
} CW;zviH5
W{Qb*{9
j'*.=cwsp
public void splitterStop() o.$48h(
{ :F d1k Jm
bStop = true; Rd(8j+Q?ps
} n6[shXH
I/'>MDB!
hMupQDv/I
} "]^U(m>f
+@$VJM%^7b
M_O$]^I3w
/* (,"%fc7<i
**FileAccess.java )g=mv*9>
*//文件访问(定位，写) 0ytAn+/"x
package NetFox; 6l|L/Z_6
import java.io.*; l[ko)%7V
g=KK PSK
!yg &zzP*
public class FileAccessI implements Serializable{ uWGp>;meO
02 FLe*zQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :Gz$(!j1.'
RandomAccessFile oSavedFile; 4FnePi~i
long nPos; nUY)LnI
C\rT'!Uk\Q
FoIK, MdJ
public FileAccessI() throws IOException 7<kr|-
{ va~:Ivl-)
this("",0); \>T1&JT
} D_\HX9
x8z6 <
:z?T/9,C
public FileAccessI(String sName,long nPos) throws IOException [L7S`Z
{ d*!H&1L
oSavedFile = new RandomAccessFile(sName,"rw"); 6 y"r'
this.nPos = nPos; GDj_+G;tO\
oSavedFile.seek(nPos); )p!") :'fv
} m:EYOe,w
sS)tSt{C
r& RJ'z
public synchronized int write(byte[] b,int nStart,int nLen) aSm</@tO&
{ F0m[ls$
int n = -1; Z(E.F,k
try{ P^-x
oSavedFile.write(b,nStart,nLen); z:n JN%Qb
n = nLen; "{{@N4^
} E?0RR'
catch(IOException e) N}|1oQkjf
{ \ }-v
e.printStackTrace (); JjAO9j%
} kSJ:4!lFU
6{Bvl[mhI
xoSBMf
return n; rI:]''PR
} I1ibrn
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} .bMU$O1
7 dG_E]&
IetV]Ff6
/* qyzeAK\Ia
**SiteInfoBean.java :)e/(I]
*/ w68VOymD/
package NetFox; piUfvw
Z*5]qh2r8
/3vj`#jD
public class SiteInfoBean { :;x#qtv~Iz
V> eJ
H%c{ }F
private String sSiteURL; //Site's URL 2wh{[Q2f
private String sFilePath; //Saved File's Path 6~+?DIc
private String sFileName; //Saved File's Name PI")^`
private int nSplitter; //Count of Splited Downloading File Kib?JRYt
Boa?Ghg
CV,[x[L#{
public SiteInfoBean() |Oaj Jux
{//nSplitter的缺省值为5 T\HP5&
//default value of nSplitter is 5 "V_PWEi
this("","","",5); zPoIs@
} YI?y_S
q}R"
yYTiAvN
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z//6yr
{ ph1veD<ZZ
sSiteURL= sURL; D&)gcO`\
sFilePath = sPath; WxLILh
sFileName = sName; ZGOI8M]@
this.nSplitter = nSpiltter; 1z(y>`ZBq
?G-a:'1!6
mE]W#?
} xH8nn3U
l>9ZAI\^
[!:.9
public String getSSiteURL() _zO,VL
{ Xl%&hM
return sSiteURL; 71w$i 4
} \bb,gRfP
,G,T&W
:FdV$E]]<
public void setSSiteURL(String value) S,v9\wN.
{ 'm"H*f
sSiteURL = value; ji2if.t@
} 2S8/ lsB
.,x08M
Hp":r%)
public String getSFilePath() B: uW(E
{ UeT"v?zP
return sFilePath; ^f1}:g
} R16"lG
Nr7MSFiL
_"F(w"|
public void setSFilePath(String value) F+AShh
{ s4}}MV3X
sFilePath = value; v1zJr6ra9
} ]}G(@9
{{=7mbc
U1rh[A>
public String getSFileName() eGLLh_V"
{ Md_\9G .e
return sFileName; f5/ba9nI
} }`
.)u,sYZA|
$- #M~eZv
public void setSFileName(String value) +2W#=G
{ lTdYPqMi
sFileName = value; -acW[$t
} 'L0 2lM
#!y|cP~;I
XUUS N
public int getNSplitter() 5'>(|7~%\
{ @eT!v{o
return nSplitter; i' |S g
} F=^vu7rf
O*yc8fUI
CWI(Q`((>
public void setNSplitter(int nCount) }(TZ}* d
{ 7,jh44(\=
nSplitter = nCount; kS?!"zk>
} m=NX;t
} 0t*q5pAG".
HPwmi[
D[]vJ
/* +69sG9BA
**Utility.java Z^`>;n2
*/ p#J}@a
package NetFox; Ql\{^s+
cKK 1$x
a*S4rq@
public class Utility { ZZFa<AK4
iu&'v
1"~@UcJ
public Utility() (h|l$OL/
{ P*R`3Y,
&gcKv1a\
|7UR_(}KC
} }3^t,>I=,6
t~ Q{\!
//线程睡眠 Eh0R0;l5>
public static void sleep(int nSecond) /[t]m,p$yq
{ Kv!CL9^LX7
try{ Ck(D: % ~s
Thread.sleep(nSecond); U{n 0Z
} >,A:zbs&
catch(Exception e) e/F=5_Io
{ m/%sBw\rx
e.printStackTrace (); =f{V<i~q
} AXz'=T}{
} *V3}L Z
`gD'q5.z;3
//日志 KS1Z&~4
public static void log(String sMsg) [|xHXcW
{ *#+XfOtF
System.err.println(sMsg); )DfmO
} xhj A!\DS
W<u63P
RBJgQ<j8
public static void log(int sMsg) hf8=r5j=
{ mn?< Zz
System.err.println(sMsg); XQ%*U=)s
} d1D{wZ3g
} \O^b|0zc
$^y6>@~
H)G ^ Y1
/* @T|mHfQ8
**TestMethod.java o-_0
*/ ?o"wyF A*
package NetFox; yx4B!U
t+W+f
Wb68")$
public class TestMethod { k6QQoLb$V
aRC>pK.
kNMhMEez
public TestMethod() Gnr]qxL
{ ///xx/weblogic60b2_win.exe +D*b!5[
try{ 12~zS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~}z{RE($v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); wt? 8-_
SiteFileFetch fileFetch = new SiteFileFetch(bean); ` Cdk b5
fileFetch.start(); KtA0 8?B
} L/1?PM
catch(Exception e){e.printStackTrace ();} nG1mx/w
~Wm`SIV
iKu[j)F
} XD<7d")I
Ultx|qU
t IdH?x
public static void main(String[] args) &$.Vi&{.
{ vS6}R5
new TestMethod(); cmmH)6c>
} }"06'
} `Yn^ -W
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