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)); .lcI"%>
} ox}LC,!
for(int i=0;i<nEndPos.length-1;i++) MO1t0Myc
{ ;Wo\MN
nEndPos = nStartPos[i+1]; +!'rwD
} +A=*C
nEndPos[nEndPos.length-1] = nFileLength; .b3cn
} b`TA2h
} Q\!0V@$
@D'NoA@1A
c~bTK" u
//启动子线程 =}8:zO 2'{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;X9nYH
for(int i=0;i<nStartPos.length;i++) f{[]m(X;
{ ,j'>}'wG)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N1pw*<&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \nX5$[
nStartPos,nEndPos,i); m4 :|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0\Q/$#3
fileSplitterFetch.start(); cTq}H_hC
} Zy<gA >
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s={jwI50
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A.D@21py
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e2P ds`
nEndPos = " + nFileLength); H7I&Ky
// fileSplitterFetch[nPos.length-1].start(); @$e!|.{1q
szDd!(&pv
L{2KK]IF
//等待子线程结束 3T<aGW1
//int count = 0; RV&=B%w+
//是否结束while循环 $_u9Y!
boolean breakWhile = false; 7*a']W{aJ
i6.HR?n
9"jhS0M
while(!bStop) o'`:$ (
{ ipIexv1/S
write_nPos(); :*/'W5iM
Utility.sleep(500); 1Re5)Y:i
breakWhile = true; /W vgC)
8 <~E;:
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for(int i=0;i<nStartPos.length;i++) ~zcHpxO^W
{ d/m.VnW
if(!fileSplitterFetch.bDownOver) IwR/4LYI
{ #y?iUv
breakWhile = false; =Eh~ wm
break; sNF[-,a
} Kc%GxD`
} 3fb"1z#
if(breakWhile) pow.@
break; 5*n3*rbU:
v&8%t 7|
-9f> rH\3
//count++; a%fMf[Fu
//if(count>4) j3J\%7^i
// siteStop(); TsvF~Gdp
} (;Ad:!9{
DO^K8~]
R)<PCe`vf
System.err.println("文件下载结束！"); +@j@#~=K
} JF+E.-fy$
catch(Exception e){e.printStackTrace ();} )[c@5zy~*
} ^e1Ux
kt0ma/QpP
:B(vk3;U!
//获得文件长度 \'BA}v &/
public long getFileSize() ;:%*h2
{ zFq8xw
int nFileLength = -1; c^?+"7oO0
try{ B9&$sTAB
URL url = new URL(siteInfoBean.getSSiteURL()); $U]KIHb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P>i!f!o*I
httpConnection.setRequestProperty("User-Agent","NetFox"); nKO4o8js{{
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int responseCode=httpConnection.getResponseCode(); ?_VoO
if(responseCode>=400) 4$wn8!x2|
{ ^`MGlI}
processErrorCode(responseCode); f\{ynC2m
return -2; //-2 represent access is error -%g$~MZ?'
} 5g$]ou
}%@q; "9`
dpTeF`N
String sHeader; d hp-XIA;
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h3<L,Olp
for(int i=1;;i++) ?|`Ba-
{ n'42CE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J'=iEI
//Utility.log(in.readLine()); hA6D*8oXD
sHeader=httpConnection.getHeaderFieldKey(i); #ox&=MY
if(sHeader!=null) RdirEH*H
{ 8vK$]e36
if(sHeader.equals("Content-Length")) Y]33:c_;Mo
{ ^qro0]"LD
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (:spA5
break; G%RL8HU
} &Oxf^x["]
} 3om_Z/k
else +'@j~\>^yJ
break; nc.(bb),
} 2jUEL=+Y
} FD+y?UF
catch(IOException e){e.printStackTrace ();} 5r-OE-U{
catch(Exception e){e.printStackTrace ();} .:nV^+)
hbOyrjanx
NhgzU+)+
Utility.log(nFileLength); L2jjkyX]
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GlPd)m`
return nFileLength; xX5EhVR
} gI/#7Cr
_?YP0GpU
3R=R k
//保存下载信息（文件指针位置） I=DvP;!
private void write_nPos() 3`mM0,fY
{ G""L1?
try{ +pefk+
output = new DataOutputStream(new FileOutputStream(tmpFile)); vK10p)ZV
output.writeInt(nStartPos.length); 9bxBm
for(int i=0;i<nStartPos.length;i++) e-`=?tct
{ Pcs62aE
// output.writeLong(nPos); @N%/v*
output.writeLong(fileSplitterFetch.nStartPos); '@WpJ{]A
output.writeLong(fileSplitterFetch.nEndPos); 'PBuf:9lN
} z K+C&X
output.close(); I/HcIBJ
} jMP!/t :w
catch(IOException e){e.printStackTrace ();} w9W0j
catch(Exception e){e.printStackTrace ();} 0?0$6F
} .GM}3(1fX`
f0h^ULd
RaBq@r*(
//读取保存的下载信息（文件指针位置） t V:oBT*
private void read_nPos() $}TK,/W
{ XeJ|Z)qZ
try{ `-J$7)d@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WYayr1
int nCount = input.readInt(); dZ"B6L!^(
nStartPos = new long[nCount]; itpljh
nEndPos = new long[nCount]; A{QXzoWkg0
for(int i=0;i<nStartPos.length;i++) ]5_6m;g
{ I.qP$j
nStartPos = input.readLong(); ?vd_8C2B
nEndPos = input.readLong(); y. A]un1
} $UX^$gG
input.close(); pT;{05
} .vm.g=-q
catch(IOException e){e.printStackTrace ();} (0cL! N;;
catch(Exception e){e.printStackTrace ();} bY>JLRQJ-
} ~ZN]2}
O*:8gu'Y2
RhPEda2
private void processErrorCode(int nErrorCode) :9=J=G*
{ Q 6)5*o8n
System.err.println("Error Code : " + nErrorCode); L( B(x>w
} 33*NgQ;&~'
i=ztWKwKf
>,#73u#
//停止文件下载 ,];4+&|8kW
public void siteStop() [&B}{6wry
{ @=0O'XM
bStop = true; &M5_G$5n
for(int i=0;i<nStartPos.length;i++) eKT'd#o2R
fileSplitterFetch.splitterStop(); -j<g}IG
}p <p(
+I9+L6>UR
} i,h)
} eLd7|*|
//负责部分文件的抓取 4YmN3i
**FileSplitterFetch.java ^UJ#YRzi
*/ `"#0\Wh
package NetFox; zq?Iwyo
;Bs^+R7
NETji:d
import java.io.*; (K}Md~
import java.net.*; qOi3`6LCV
4wa8Vw`
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public class FileSplitterFetch extends Thread { Mb2rHUr
J(s%"d
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String sURL; //File URL SjZ?keKZ
long nStartPos; //File Snippet Start Position S(b5Gj/Kd
long nEndPos; //File Snippet End Position OGC|elSM
int nThreadID; //Thread's ID (ru9Ke%Dx
boolean bDownOver = false; //Downing is over !8#!P
boolean bStop = false; //Stop identical 5ZPe=SQ{
FileAccessI fileAccessI = null; //File Access interface ;44?`[oP
(_Ld^^|
S[_Hc$7U
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'B$bGQ
{ vcsMU|GGh
this.sURL = sURL; *YhX6J1
this.nStartPos = nStart; 8r 4 L4
this.nEndPos = nEnd; qZ8V/
nThreadID = id; yzml4/X
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u{@b_75Y
} ST^@7f_
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"E><:_,\
public void run() t\p_QWnF
{ !{L6 4qI
while(nStartPos < nEndPos && !bStop) S(5aJ[7Zm
{ F%v?,`_&I
OFtAT@=O
>;ucwLi
try{ TN=MZ{L
URL url = new URL(sURL); sT^^#$ub
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OSvv\3=
httpConnection.setRequestProperty("User-Agent","NetFox"); lk5}bnd5
String sProperty = "bytes="+nStartPos+"-"; O0lQ1<=
httpConnection.setRequestProperty("RANGE",sProperty); SAa hkX
Utility.log(sProperty); /wjL<
_DAAD,'<a
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InputStream input = httpConnection.getInputStream(); D-zqu~f`
//logResponseHead(httpConnection); I'_.U]An
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byte[] b = new byte[1024]; t-vH\m
int nRead; & q(D90w.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~IB~>5U!
{ zqq$PaH*
nStartPos += fileAccessI.write(b,0,nRead); xV h-Mx+M
//if(nThreadID == 1) mST/u>'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -6+&?f
} #\&jM -.-
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E+65
Utility.log("Thread " + nThreadID + " is over!"); JQ*CF(9
bDownOver = true; D\:~G}M
//nPos = fileAccessI.write (b,0,nRead); sf|[oD
} TV>UD q
catch(Exception e){e.printStackTrace ();} CVi3nS5Yl
} ;tR,w
} pGy]t
}v[$uT-q
(> v1)*r
//打印回应的头信息 Tv;|K's'
public void logResponseHead(HttpURLConnection con) ]0HlPP:2
{ 0%
for(int i=1;;i++) [-@Lbu-|
{ FafOd9>AO
String header=con.getHeaderFieldKey(i); .<|7BHL
if(header!=null) +^c;4-X 0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >Fzu]G4]
Utility.log(header+" : "+con.getHeaderField(header)); !J}Bv
else Xegg2.Kk
break; ;UU+:~
} (i,TxjS'od
} FS%Xq-c
0<+=Ew5Z
crJyk#_
public void splitterStop() OG_2k3v
{ CapWn~*g
bStop = true; W*hRYgaX3
} c%uX+\-$
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eeuTf
} %#rH~E
3N) bJ
3B(6^iS
/* \advFKN
**FileAccess.java xQ `>\f
*//文件访问(定位，写) t` R#pQ
package NetFox; ,H3~mq]
import java.io.*; xj/ +Z!,9
nQc]f*
+h6cAqm]
public class FileAccessI implements Serializable{ )g9&fGYf
R4<}kA,.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 F6gboo)SD
RandomAccessFile oSavedFile; Q0f7gY1-%
long nPos; ZJ} V>Bu-
i/nA(%_
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public FileAccessI() throws IOException 9S0I<<m
{ r*K[,
this("",0); lPh>8:qFM
} qV$\.T>x
v1yNVs\}
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public FileAccessI(String sName,long nPos) throws IOException 'IweN
{ (u81p
oSavedFile = new RandomAccessFile(sName,"rw"); Tp.0@aC
this.nPos = nPos; r00 fvZyK
oSavedFile.seek(nPos); S x';Cj-
} "-Lbz)k
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public synchronized int write(byte[] b,int nStart,int nLen) C>q,c3s5
{ V:rq}F}
int n = -1; **V^8'W<
try{ ">}l8MA
oSavedFile.write(b,nStart,nLen); y K~;LV
n = nLen; a%"My;8
} dnVl;L8L3
catch(IOException e) @,D 3$P8}
{ )W!8,e+%
e.printStackTrace (); 8[SiIuIV
} [kx_Izi/T
2T &<jt
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return n; `1F[.DdF
} >&mlwxqv
cB U,!
, ;L
} k=2]@K$%
"8wRxDr+
`s (A&=g\
/* .'C$w1[w
**SiteInfoBean.java &Avd
*/ Yxye?R-:
package NetFox; <o^_il$W
$j*j {}K
r>1M&Y=<
public class SiteInfoBean { [?mDTD8zU
Y,OSQBgk
P g.PD,&U
private String sSiteURL; //Site's URL 6LRI~*F=3
private String sFilePath; //Saved File's Path m!3L/UZ
private String sFileName; //Saved File's Name Ml` f+$
private int nSplitter; //Count of Splited Downloading File EOu\7;kE9
6CBk,2DswI
L;=:OX0
public SiteInfoBean() & IVwm"
{//nSplitter的缺省值为5 $Scb8<
//default value of nSplitter is 5 7u]0dHj
this("","","",5); ]q DhGt
} aJlSIw*Q,
Be+CV">2
$E@L{5Yt
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ">]v'h(s
{ [Q&{#%M
sSiteURL= sURL; N"MuAUB:K
sFilePath = sPath; pqO}=*v@
sFileName = sName; 2Q`@lTUv
this.nSplitter = nSpiltter; 6/@"K HHVe
ZcgSVMqEX
@e#eAJhU
} :SilQm*Pl
8munw
6k"'3AKaR
public String getSSiteURL() keNPlK%>
{ mHjds77e
return sSiteURL; pIdJ+gu(s
} |[n-H;0
O7|0t\)
Kl<qp7o0
public void setSSiteURL(String value) :9N~wd
{ {7&(2Z]z
sSiteURL = value; v]|^.x:
} 9E^IEwq'
bj4cW\b(
_y&m4Vuu
public String getSFilePath() !4cR&@[
{ E\Hhi.-
return sFilePath; z5-vx`
} R,CFU l7Q
L6yRN>5aE
ucQ2/B#'4l
public void setSFilePath(String value) Mw2?U>h1
{ -M}#-qwf
sFilePath = value; ;u!qu$O
} 0Qvbc}KP8
4*W ??(=j
PLR[nB7K
public String getSFileName() E+Z//)1Z
{ v# ab2
return sFileName; @K/}Ob4
} O1IR+"0
=M^4T?{T
BuMBnbT
public void setSFileName(String value) Reca5r1O
{ zK893)
sFileName = value; R'f|1mt
} `9rwu:3i
$wUFHEl
(yWU9q)5
public int getNSplitter() GFasGHAw
{ u5^fiw]C
return nSplitter; y&Sl#IQ L
} mDz{8N9<FG
mw%do&e
e`ti*1]q
public void setNSplitter(int nCount) P3se"pP
{ f3Ior.n(
nSplitter = nCount; P.mz$M
} -o*IJQ_
} V.5gxr3QqW
}I<r=?
8B;wn<O
/* @ qWgokf
**Utility.java 6j{9\ R
*/ pMM,ox"
package NetFox; f$$l,wo
$}&Y$w>S
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public class Utility { _]8FCO
|f1 S&b.
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public Utility() {pMbkAQ@
{ hI*gw3V
@~%R%Vu
9,\b$?9
} |D<J9+
~*RG|4#
//线程睡眠 i-[ic!RnKj
public static void sleep(int nSecond) >2l1t}"\
{ 5Z/xY&
try{ 89T xd9X
Thread.sleep(nSecond); XB*)d 9'8
} |?{3&'`J8w
catch(Exception e) IiTV*azVh
{ >aXyi3B
e.printStackTrace (); p\OUxAm
} c}GmS@
} k4jZu?\C]
WrH7tz
//日志 4b]/2H
public static void log(String sMsg) \U $'3M
{ p2 u*{k{
System.err.println(sMsg); mUY+v>F
} `s93P^%
]V*s-och'
:U_k*9z}=
public static void log(int sMsg) cM%I5F+n
{ _$%.F|:
System.err.println(sMsg); _7r<RZ
} RGFanP
} "L^]a$&
<uZ r.X
vw VeHjR
/* @\0U`*]^)
**TestMethod.java 0`%eP5
*/ \M0-$&[+Z
package NetFox; ?145^ w
;sd[Q01
Z.6M~
public class TestMethod { vAWJP_;J
Bfe#,
F N6GV
public TestMethod() ,:POo^!/fT
{ ///xx/weblogic60b2_win.exe ) =-$>75Z
try{ t}L kl(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4FURm@C6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Nn<TPT[,
SiteFileFetch fileFetch = new SiteFileFetch(bean); wdg,dk9e$
fileFetch.start(); =K'X:UM
} AjBwj5K
catch(Exception e){e.printStackTrace ();} _N!L?b83P
2"+8NfFl
" &2Kvsz
} "D#+:ix8G|
91%QO?hz
BSt^QH-'
public static void main(String[] args) KZoIjK]
{ ~I[Z2&I
new TestMethod(); "TW%-67
} y#F`yXUj
} rTTde^^_
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