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)); F%4N/e'L
} D |fo:Xp,
for(int i=0;i<nEndPos.length-1;i++) _ q AT%.
{ 1#8~@CQ ::
nEndPos = nStartPos[i+1]; >FJK$>[1:p
} R]RLy#j
nEndPos[nEndPos.length-1] = nFileLength; 9$}>O]
} 02)Ybp6y
} 'Mhnu2d
54/ZGaonz
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//启动子线程 |tz{Es<`B
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !3o/c w9
for(int i=0;i<nStartPos.length;i++) _@VKWU$$
{ i8DYC=r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Hl*#iUq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), nA%8 bZ+
nStartPos,nEndPos,i); bjN"H`Q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F=f9##Y?7M
fileSplitterFetch.start(); wRq f'
} 4VkJtu5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AgB$ w4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1F+nWc2b
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Mko,((>I1
nEndPos = " + nFileLength); f9hH{(A
// fileSplitterFetch[nPos.length-1].start(); ^K 9jJS9K
zm4e+v-
,4}s 1J#
//等待子线程结束 2P{! n#"
//int count = 0; &ha<pj~
//是否结束while循环 A5O;C
boolean breakWhile = false; I;9DG8C&v*
n@S|^cH
%6Y}0>gY
while(!bStop) e`)zR'As
{ QqcAmp
write_nPos(); >R.!Qze\G
Utility.sleep(500); GB>T3l"
breakWhile = true; N'|9rB2e
/)rv Ndn
U]ZI_[\'U
for(int i=0;i<nStartPos.length;i++) t1G2A`
{ =S\pI
if(!fileSplitterFetch.bDownOver) y@Td]6|f
{ :%U lNk
breakWhile = false; P%<MQg|k`
break; tcI Z 2H%
} mk6>}z*
} t,kai6UM
if(breakWhile) 4hn'b[
break; 'ztY>KVj
g=Nde2d?
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//count++; t /lU*
//if(count>4) Owh:(EJ"d
// siteStop(); AO8%!+"_
} V<d`.9*}
ETfoL.d$(
+V#dJ[,8;.
System.err.println("文件下载结束！"); ,@Elw>^
} 8=mx5Gwz-
catch(Exception e){e.printStackTrace ();} xJFxrG'c
} 6O'Y@9#
X\BdN Hr
qi8~bQ{rH
//获得文件长度 (T",6xBSG
public long getFileSize() kB-<17
{ quFNPdP
int nFileLength = -1; Q*/jQC
try{ }/7rA)_
URL url = new URL(siteInfoBean.getSSiteURL()); Angt=q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Wix4se1Ac
httpConnection.setRequestProperty("User-Agent","NetFox"); ) =|8%IrB
D]K?ntS[*
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int responseCode=httpConnection.getResponseCode(); }]j#C
if(responseCode>=400) Kq:vTz&<
{ 8`q"] BQN
processErrorCode(responseCode); Vv>hr+e
return -2; //-2 represent access is error w5a;ts_x
} [ _&z+
<{.pYrn
!:1BuiL
String sHeader; r#^uY:T%
~|`jIqU
eak+8URo
for(int i=1;;i++) {CGk9g"`
{ {)-3g~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4aG}ex-s|
//Utility.log(in.readLine()); ,L8(Vo`-
sHeader=httpConnection.getHeaderFieldKey(i); gq)uv`3
if(sHeader!=null) 7:OF>**
{ p[D,.0SuC
if(sHeader.equals("Content-Length")) iD:TKB_r
{ ^~m}(6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +kOXa^K
break; Q_|Lv&
} #vT~D>zj
} 3n1 >+8
else \B8[UZA.&
break; [S[@ Q[zP@
} CSMx]jbb
} r7*'s
catch(IOException e){e.printStackTrace ();} HO39>:c
catch(Exception e){e.printStackTrace ();} M}9PicI?7
?/Z5%?6
_MUSXB'
Utility.log(nFileLength); $`Aps7A
k)S'@>n{u
O)}5`0@L
return nFileLength; ?,*KAGg%
} 9H~OC8R:
Ert` ]s~
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//保存下载信息（文件指针位置） /@K1"/fqH
private void write_nPos() O@,9a~Ghd
{ )dI `yf
try{ RMBPm*H
output = new DataOutputStream(new FileOutputStream(tmpFile)); UQ+!P<>w
output.writeInt(nStartPos.length); !a9/8U_>XF
for(int i=0;i<nStartPos.length;i++) Uj>bWa`
{ k!sk\~>YO
// output.writeLong(nPos); -Sj|Y}
output.writeLong(fileSplitterFetch.nStartPos); gJuA*^
output.writeLong(fileSplitterFetch.nEndPos); LT)G"U~
} ~ ^)4*@i6
output.close(); [xg&`x9,.
} xX{gm'3UYa
catch(IOException e){e.printStackTrace ();} dL>8|
catch(Exception e){e.printStackTrace ();} ?h'd\.j{
} UWq[K&vQZ
#Ue_
C(5B/W6
//读取保存的下载信息（文件指针位置） dO\irv)
private void read_nPos() ^EmI;ks
{ Y` tB5P
try{ f hr QJ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h$q=NTV
int nCount = input.readInt(); L:RMZp*bK
nStartPos = new long[nCount]; F<A[S"
nEndPos = new long[nCount]; RJT=K{2x
for(int i=0;i<nStartPos.length;i++) Ce_ES.
{ ma(E}s
nStartPos = input.readLong(); =aE!y5
nEndPos = input.readLong(); ayoqitXD?
} m8<l2O=m
input.close(); YCEdt>5PA
} G,JNUok
catch(IOException e){e.printStackTrace ();} rP7f~"L
catch(Exception e){e.printStackTrace ();} %oqC5O6
} Dg2=;)"L
u}I\!-EX!v
q3-V_~5^/z
private void processErrorCode(int nErrorCode) E]j2%}6Z%
{ 8\@&~&(y:
System.err.println("Error Code : " + nErrorCode); W: vw.
} mu}T,+9\
Q7@.WG5
a}MSA/K(
//停止文件下载 x7l3&;yDv
public void siteStop() |]8Hh>
{ 0413K_
bStop = true; Pf?y!dK<
for(int i=0;i<nStartPos.length;i++) ts3BmfR?
fileSplitterFetch.splitterStop(); Auz.wes
(r+#}z}
fd} Ul
} }D>nXhO&
} ^%pM$3ov
//负责部分文件的抓取 ^q=D!g
**FileSplitterFetch.java Ot#O];3
*/ :;(zA_-
package NetFox; '8b/TL
'Bv)UfZ
0kdPr:B Q0
import java.io.*; |p"E0av
import java.net.*; kxp, ZP
Vx6/Rehj
ni$S@0
public class FileSplitterFetch extends Thread { qvH7otA
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%8a886;2
String sURL; //File URL Rg!Fu
long nStartPos; //File Snippet Start Position 3j iSvrfI
long nEndPos; //File Snippet End Position q`8M9-~
int nThreadID; //Thread's ID *>a+`|[1*
boolean bDownOver = false; //Downing is over \Gk4J<
boolean bStop = false; //Stop identical G$B( AWL
FileAccessI fileAccessI = null; //File Access interface :"4Pr/}rT
DcQ[zdEz+
_z$lg]q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "+6:vhP5
{ 8;C_@
this.sURL = sURL; feH|sz`e
this.nStartPos = nStart; 30fsVwE2
this.nEndPos = nEnd; l12_&o"C~
nThreadID = id; {T0f]]}Q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z"@yE*6
} } :@s
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:bhpYEUMx
public void run() ` 5.PPI\h2
{ JQhw>H9&
while(nStartPos < nEndPos && !bStop) `T gwa
{ Vg0$5@
vIi#M0@N
mrzrQ@sN
try{ \[Dxg`;4
URL url = new URL(sURL); i8\&J.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _djr>C=H"
httpConnection.setRequestProperty("User-Agent","NetFox"); c<`Z[EY(t
String sProperty = "bytes="+nStartPos+"-"; 5gPcsn"D
httpConnection.setRequestProperty("RANGE",sProperty); TfYXF`d
Utility.log(sProperty); }T}9AQ}|
){PL6|5x
\UdHN=A&
InputStream input = httpConnection.getInputStream(); 8e`'Ox_5a
//logResponseHead(httpConnection); gRk%ObJGqm
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G/2| *H
byte[] b = new byte[1024]; 3=reN6Q
int nRead; 5w\>Whbd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -gWqq7O
{ meHnT9a^
nStartPos += fileAccessI.write(b,0,nRead); D]H@Sx
//if(nThreadID == 1) :Kl~hzVSOa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aIrQ=}
} 'Y ZYRFWXM
t4a/\{/#9|
RJo"yB$1e6
Utility.log("Thread " + nThreadID + " is over!"); 7>Af"1$g
bDownOver = true; 8| 6:
//nPos = fileAccessI.write (b,0,nRead); C6=P(%y
} {xw"t9(fE
catch(Exception e){e.printStackTrace ();} 'w?*4H
} CnJrJ>l
} 9aED6
tFY;q##z
Mpfdl65
//打印回应的头信息 gy Jx>i
public void logResponseHead(HttpURLConnection con) s~@4
{ tSr.0'CE
for(int i=1;;i++) ;b(*Bh<
{ `CWI%V
String header=con.getHeaderFieldKey(i); Op&i6V}<s
if(header!=null) gEVN;G'B<=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {bxTODt@
Utility.log(header+" : "+con.getHeaderField(header)); wj-=#gyAoo
else ?onaJ=mT
break; PdUlwT?8C
} mgIB8D+6
} jE /pba4R
xWwQm'I2}
7oPLO(0L
public void splitterStop() qq%\
{ {*gO1TZt9
bStop = true; ~ .}
} ~uF%*
w4m-DR5
^sLnKAN
} }:5_vH0
hJrcy!P<a
cQ= "3M)~r
/* X@;o<2^
**FileAccess.java *Nv!Kuk
*//文件访问(定位，写) -8j<`(M'5
package NetFox; >/*wlY!E
import java.io.*; L/2{}l>D
~FnB!Mh}?
2~:jg1
public class FileAccessI implements Serializable{ +(v<_#wR-
>EVlMt27'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 N!7r~B
RandomAccessFile oSavedFile; 7MRu=Z.-b
long nPos; 28 h3Ayw4
:lF[k`S T
!1i(6?~#4
public FileAccessI() throws IOException yc./:t1at>
{ N|Cx";,|FZ
this("",0); / v";u)
} c\X0*GX
[x`trypg
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public FileAccessI(String sName,long nPos) throws IOException tTWeOAF
{ <SiD m-=E
oSavedFile = new RandomAccessFile(sName,"rw"); 6XVr-ef
this.nPos = nPos; deD%E-Ja
oSavedFile.seek(nPos); K\Oz ~,z
} RR2Q
0_Gi1)
68m (%%E@
public synchronized int write(byte[] b,int nStart,int nLen) VieX5
{ w]Q0}Z
int n = -1; /u9Md3q*'
try{ ,@+7(W
oSavedFile.write(b,nStart,nLen); E0K'|*
n = nLen; MA\^<x_?L}
} k+X=8()k
catch(IOException e) {@T8i^EI
{ ]B;GU
e.printStackTrace (); Ri$wt.b
} B{fPj9Y0
~7Ji+AJA
s?;rP,{:p
return n; Z]$RO
} 1WGcv O)<
2?3D` `
t;P%&:"@M
} !olvP*c"
[ vU$zZ<
O34'c_ fZ
/* W"9?D
**SiteInfoBean.java e:9CD-
*/ mZ;W$y SO
package NetFox; "Aw| 7XII
_Je k;N
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public class SiteInfoBean { Dq/ _#&S
s: c
SK2nxZOH
private String sSiteURL; //Site's URL [aM_.[bf
private String sFilePath; //Saved File's Path [m*=Q
private String sFileName; //Saved File's Name l~.}#$P]
private int nSplitter; //Count of Splited Downloading File "yR56`=
&KfRZ`9H
PV?XpT
public SiteInfoBean() 7g(,$5
{//nSplitter的缺省值为5 m?;aTSa
//default value of nSplitter is 5 <v<TsEI
this("","","",5); )A]E:]2
} 3zJbb3e
6&(gp(F
b*4[)Yg4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Hu$]V*rAG
{ H-%)r&"vn
sSiteURL= sURL; *wW/nr=\;
sFilePath = sPath; !:Lb^C;/
sFileName = sName; Q1qf'u
this.nSplitter = nSpiltter; '>:mEXK}w
F^kH"u[
mk JS_6
} 6[BQx)7T
lhm=(7Y
1nh2()QI[
public String getSSiteURL() }+U} [G
{ #84pRU~
return sSiteURL; H27J kZ&
} 0dhJ# [Y
Dx/!^L02
ehEXC
public void setSSiteURL(String value) $rf4h]&<
{ '>(R'g42n
sSiteURL = value; J&~nD(&TY
} i70TJk$fs
4VE7%.z+
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public String getSFilePath() Qg+0(odd
{ 2Mx9Kd'a r
return sFilePath; P>%\pCJ])
} nGA'\+zjL
}9fH`C/m
ShanwaCDqv
public void setSFilePath(String value) ouKID_'
{ U6qv8*~
sFilePath = value; >`DbT:/<
} !Y_"q^5GG'
s)%RmsdL
Xr~6_N{J
public String getSFileName() eW)(u$C|qL
{ l)E \mo 8
return sFileName; -}k'a{sj=
} i> Ssp
*zX*k7LnV
e47JLW&b
public void setSFileName(String value) 'Omi3LXfDT
{ v=?U{{xQ
sFileName = value; ?iG}Qj@5
} ]B0>r^
b3e:F{n ^
V#!ihL/>
public int getNSplitter() MrjET!`.jC
{ zmy94Y5PE
return nSplitter; F.?`<7
} %>'2E!%
(A?{6
VP=(",`
public void setNSplitter(int nCount) 9}kN9u
{ { 'Hi_b3
nSplitter = nCount; ^[XxE Lx
} IXt2R~b
} 8%JxXtWW`
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w.J[3m/
/* 8^=g$;g
**Utility.java (r`+q[
*/ m}0US;c#f
package NetFox; I.tJ4
8 f%@:}H
c\UVMyE
public class Utility { |x["fWK
]CH@T9d5V
:N^1T6v
public Utility() )eGGA6G
{ 8YraW|H
#/@U|g
xBU\$ToC
} g~.,-V}
`|wH=
//线程睡眠 OYC4iI
public static void sleep(int nSecond) ;6t>!2I>C
{ SqFya
try{ $-"AMZ899
Thread.sleep(nSecond); 8,YF>O&
} _)2.#L
catch(Exception e) RGhl`;
{ v83uGEq(
e.printStackTrace (); hxx,E>k
} xPb;_~
} 4C[,S|J
;|w &n
//日志 # j*$ `W;
public static void log(String sMsg) nFW^^v<
{ '0X!_w6W
System.err.println(sMsg); twt Bt L
} |`s}PcV
s8}:8
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public static void log(int sMsg) x`PIJE
{ =b32E^z,
System.err.println(sMsg); b@^M|h.Va
} t2p/NIn
} yt>Pf<AI
T =3te|fv
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/* h@Ea$1'e,
**TestMethod.java kR^7Z7+#*
*/ nX5*pTfjL3
package NetFox; @5 kKMz
fj0+a0h
PZNo.0M70
public class TestMethod { rZu_"bcJ
)g:UH Ns
34YYw@?}Y
public TestMethod() HCHP15otfe
{ ///xx/weblogic60b2_win.exe $DA0lY\
try{ &-<"HW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?MKf=!w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kSU5 }
SiteFileFetch fileFetch = new SiteFileFetch(bean); n#z^uq|v
fileFetch.start(); \2_>$:UoV
} :1_hQeq
catch(Exception e){e.printStackTrace ();} PC\Xm,,
x)"=*Jj
a47Btd'm
} P|h<|Gcp
bIp;$ZHy`K
hp-<8Mf
public static void main(String[] args) [2i+f<
{ 7S] h:q%%
new TestMethod(); 82$By]Y9
} yp@mxI@1
} !Q.c8GRUQ
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