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)); E}a.qM'
} !?Y71:_!
for(int i=0;i<nEndPos.length-1;i++) 7!FiPH~kM
{ D`X<b4e8/
nEndPos = nStartPos[i+1]; ^P/OHuDL
} QZa^Cng~
nEndPos[nEndPos.length-1] = nFileLength; PxvxZJf$@
} -vk/z+-^!
} aG4 ^xOD
zb02\xvf
@\xEK5SG
//启动子线程 I,,SR"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [;F!\B-
for(int i=0;i<nStartPos.length;i++) ,1lW`Krx
{ /h`gQyGuY
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x_?K6[G&}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @T>^ >
nStartPos,nEndPos,i); SkVah:cF-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )=x4+)9
fileSplitterFetch.start(); >9#) obw
} M(C}2.20
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2Dvq3VbiO"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R%)F9P$o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8oRq3"
nEndPos = " + nFileLength); ]VtP7Y
// fileSplitterFetch[nPos.length-1].start(); 5nceOG8
u(?U[pe[
0oBAJP
//等待子线程结束 B,Tv9(sv
//int count = 0; Fl{~#]
//是否结束while循环 /l3Oi@\
boolean breakWhile = false; ;pfN
tI#65ox#
0JR)-*
while(!bStop) '.S02=/
{ -ik((qx_
write_nPos(); l 6aD3?8LN
Utility.sleep(500); BePb8 k<y
breakWhile = true; Dvl\o;
sE|8a
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for(int i=0;i<nStartPos.length;i++) 9(vp`Z8B4
{ +ek6}f#
if(!fileSplitterFetch.bDownOver) %(POC=b#[
{ iS"6)#a72
breakWhile = false; DZb0'+jQ
break; m6xbO
} }XpZgd$
} ,kYX|8SO
if(breakWhile) mRGr+m
break; SNSoV3|k-
*p0n^XZ% ?
6Iz!_
//count++; HxLuJ
//if(count>4) 7*Zm{r@u
// siteStop(); <pS#wTsN4%
} F*Yx1vj
(R RRG;*n#
]_|%!/_
System.err.println("文件下载结束！"); 4Sdj#w
} /;21?o
catch(Exception e){e.printStackTrace ();} ^U,C])n
} <+b~E,
3!#FG0Z
|N 2r?b/g
//获得文件长度 a8k`Wog
public long getFileSize() 1 un!
{ Pmr'W\aIR
int nFileLength = -1; q1r-xsjV=
try{ wXBd"]G)C
URL url = new URL(siteInfoBean.getSSiteURL()); zqI|VH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j0Os]a
httpConnection.setRequestProperty("User-Agent","NetFox"); JlEfUg#*
j{=}?+M
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int responseCode=httpConnection.getResponseCode(); `G*fx=N
if(responseCode>=400) Tpkt'|8
{ #Wb4*
processErrorCode(responseCode); 5,|{|/
return -2; //-2 represent access is error NPa4I7`A
} puEu)m^
la$%%@0/
2t{Tz}g*
String sHeader; rploQF~OFF
nU#K=e =W
37M,Os1(
for(int i=1;;i++) X .K*</(g
{ { W5 _KX
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |&bucG=
//Utility.log(in.readLine()); ~rAcT6#
sHeader=httpConnection.getHeaderFieldKey(i); X~\O]
if(sHeader!=null) -ni@+Dy
{ >29c[O"[
if(sHeader.equals("Content-Length")) 6D{70onY+
{ ~=otdJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k@[[vj|W
break; 7s}F`fjKP
} nKTi"2dm
} "Z dI~
else 'S#^70kt
break; zP c54>f
} AkO-PL
} yy3`E}vX7
catch(IOException e){e.printStackTrace ();} e\*(F3r
catch(Exception e){e.printStackTrace ();} eOZ~p
tWTC'Gx-J
e?]HNy
Utility.log(nFileLength); xz+;1JAL3
7.kH="@
?1eu9;q\*
return nFileLength; ~)ysEZl
} KyqP@ {
rQpQqBu
s]D1s%Mx
//保存下载信息（文件指针位置） '#QZhz(+
private void write_nPos() {?3i^Q=V
{ ,1vFX$
try{ W(.svJUgb.
output = new DataOutputStream(new FileOutputStream(tmpFile)); z38Pi
output.writeInt(nStartPos.length); ._.Qf<7
for(int i=0;i<nStartPos.length;i++) ;9Wimf]G,E
{ J10&iCr{r*
// output.writeLong(nPos); #wh[F"zX
output.writeLong(fileSplitterFetch.nStartPos); 0p\Kf(|E*6
output.writeLong(fileSplitterFetch.nEndPos); GW.Y=S
} AD6 b
output.close(); 'BVI^H4
} {L M Q
catch(IOException e){e.printStackTrace ();} (8/&
catch(Exception e){e.printStackTrace ();} 7Q&S [])
} #!r>3W&
WO^]bR
J*^ i=y
//读取保存的下载信息（文件指针位置） P(LiH
private void read_nPos() kn&BGYt
{ 6/Z_r0^O
try{ ]XYD2fR2qA
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i&)OJy
int nCount = input.readInt(); ^Q!A4qOQ
nStartPos = new long[nCount]; Enp;-wG:-
nEndPos = new long[nCount]; koj*3@\p/
for(int i=0;i<nStartPos.length;i++) _+%p!!
{ jd}~#:FUr*
nStartPos = input.readLong(); tS,AS,vy]
nEndPos = input.readLong(); 1IK*j+%
} b~TTz`HZ
input.close(); ?U2 'L2y
} |"eC0u
catch(IOException e){e.printStackTrace ();} SxX
catch(Exception e){e.printStackTrace ();} ;9vY5CxzC
} vOtILL6
5/HkhTyj
81)i>]
private void processErrorCode(int nErrorCode) CUaL
{ JDOn`7!w
System.err.println("Error Code : " + nErrorCode); 4-C'2?
} W/%9=g$m
OA[fQH#{lX
&NI\<C7_Gw
//停止文件下载 zN\C
public void siteStop() veS) j?4
{ !0v3Lu~j
bStop = true; bPuO~#iN~
for(int i=0;i<nStartPos.length;i++) M{YN^ Kk
fileSplitterFetch.splitterStop(); ;i?R+T
}%0X7'
q'uGB fE.
} g5*?2D}dqX
} 'GLpSWL+*
//负责部分文件的抓取 GP`sOPr
**FileSplitterFetch.java TT&%[A+
*/ d?/>Qqw:#
package NetFox; *mW2vJ/B
TW1#'G_#
l}D /1~d
import java.io.*; ( F4c0
import java.net.*; $JiypX^DOP
?5j~"
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public class FileSplitterFetch extends Thread { 0*AXd=)"*
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cPg{k}9Tvy
String sURL; //File URL ,z>w^_
long nStartPos; //File Snippet Start Position *thm)Mn
long nEndPos; //File Snippet End Position wv Mp~
int nThreadID; //Thread's ID P5lk3Zg'
boolean bDownOver = false; //Downing is over isFxo,R9r
boolean bStop = false; //Stop identical bP4}a!t+n
FileAccessI fileAccessI = null; //File Access interface 2{B ScI5K
?^`fPH=
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {~XnmBs
{ @eq.&{&
this.sURL = sURL; pfFHuS~
this.nStartPos = nStart; B_XX)y%V
this.nEndPos = nEnd; uhB V)Qg
nThreadID = id; A-YW!BT4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :Vw{ lB
} F#.ph?W
8uA!Vrp3
#WAX&<m
public void run() (]zi;
{ -]QP#_
while(nStartPos < nEndPos && !bStop) o1uM(
{ s3VD6xi7
(D{J|
Y)l=r^Ap>
try{ wNmC1HOh
URL url = new URL(sURL); d;{k,rP6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Bi>]s%zp
httpConnection.setRequestProperty("User-Agent","NetFox"); V~do6[(
String sProperty = "bytes="+nStartPos+"-"; Gz(l~!n~a
httpConnection.setRequestProperty("RANGE",sProperty); ~Bi%8G
Utility.log(sProperty); 32`Z3-
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[.&n,.k
InputStream input = httpConnection.getInputStream(); |f(*R_R
//logResponseHead(httpConnection); $KlaZ>Dh
Fqh./@o
%.HLO.A
byte[] b = new byte[1024]; =T1Xfib
int nRead; Np/vPaAk
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) F@zTz54t
{ F_4Et
nStartPos += fileAccessI.write(b,0,nRead); RF~G{wz
//if(nThreadID == 1) ;^|):x+O
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oe!4ng[
} ]bYmM@
}c>vk
D]N)
Utility.log("Thread " + nThreadID + " is over!"); k$pND,Ws
bDownOver = true; kfZ(:3W$
//nPos = fileAccessI.write (b,0,nRead); <2~DI0pp(
} >7~,w1t
catch(Exception e){e.printStackTrace ();} 0Gu?;]GSv
} "bQi+@
} 14*6+~38m&
"yj_v\@4
1/K1e$r
//打印回应的头信息 a2/Mf
public void logResponseHead(HttpURLConnection con) zS h9`F
{ w\{#nrhYU
for(int i=1;;i++) 5u3KL A
{ yB 'C9wEH
String header=con.getHeaderFieldKey(i); 9}Ge@a<j
if(header!=null) [JV?Mdzu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -= izu]Fb,
Utility.log(header+" : "+con.getHeaderField(header)); /XU=l0u
else IreY8.FND
break; 7PBE(d%m
} =K}T; c
} iSg0X8J)
# s7e/GdKb
GSd:Plc%
public void splitterStop() Wu(^k25
{ ,+I]\ZeO
bStop = true; I5`>XfO)
} 5)5yH bS
&xGpbJG
V`HnFAW
} e,lLHg
L 4Z+8*
(U_HX2f
/* =6'bGC%c
**FileAccess.java ck3+A/ !z
*//文件访问(定位，写) P"]l/
package NetFox; R0LWuE%eD
import java.io.*; _*b`;{3
#kA?*i[T
\fuz`fK:
public class FileAccessI implements Serializable{ o=K9\l
q/d?cLgl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B692Mn
RandomAccessFile oSavedFile; c\&;Xr
long nPos; v~jm<{={g
J9DI(`
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public FileAccessI() throws IOException LZ.Xcy
{ u3E =r
this("",0); &m GU
} + #E?)
dUl"w`3
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public FileAccessI(String sName,long nPos) throws IOException Z @ef2y;
{ <W)F{N?
oSavedFile = new RandomAccessFile(sName,"rw"); 8#- Nx]VM
this.nPos = nPos; mg@Ol"2
oSavedFile.seek(nPos); T?6<1nU)
} %lGOExV%
*N:0L,8
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public synchronized int write(byte[] b,int nStart,int nLen) HavlN}h
{ u86PTp+
int n = -1; 9=}[~V n
try{ lSO$Q]!9
oSavedFile.write(b,nStart,nLen); w-xigm>{Z
n = nLen; Vsw:&$
} MX7Ix{
catch(IOException e) yWE\)]9
{ p]/[ji
e.printStackTrace (); 2FV@?x0po
} "PO8Q
D6+3f#k6
~J>;l s1
return n; +R HiX!PG
} :FtV~^Z
yjH'<
\_6
} |yzv o"3
%#eQN ~
3 H5
/* &=$f\O1Ty
**SiteInfoBean.java N:k>V4oE
*/ 5U4V_*V
package NetFox; SK^(7Ws~0
W*#5Sk
fjl9*
public class SiteInfoBean { _z{9V7n4
d;wq@e
SE@TY32T
private String sSiteURL; //Site's URL wVnmT94
private String sFilePath; //Saved File's Path >/Q^.hzd
private String sFileName; //Saved File's Name zwJ&K;"y(
private int nSplitter; //Count of Splited Downloading File &FT`z"^
?wCX:?g
#\n*Qg4p
public SiteInfoBean() e@TwZ6l
{//nSplitter的缺省值为5 ztX$kX:_m
//default value of nSplitter is 5 |9IOZ>H9
this("","","",5); {=mGXd`x?l
} yt="kZ
.Y?]r6CC/
,+6u6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y,Rr[i"j
{ QT^b-~^
sSiteURL= sURL; B@i%B+qCLv
sFilePath = sPath; 7Re\*[)T
sFileName = sName; j|K;Yi
this.nSplitter = nSpiltter; 3o?eUwI}
2ww H3}
<!UnH6J.b
} {z0iWY2Xw
N#"l82^H*
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public String getSSiteURL() Tq?Ai_
{ x4L3Z__
return sSiteURL; y_Urzgm(
} U4K ZPk
V@-Q&K#
KA?%1s(kJ
public void setSSiteURL(String value) h4|}BGO
{ QSa#}vCp*
sSiteURL = value; Rk#'^}
} (B\ UZb
:Hm'o}
7g+T
public String getSFilePath() ~S;-sxoO0l
{ }8aqSD<:
return sFilePath; zb!1o0, J
} ,f:K)^yD
J9*;Bqzim
w(S~}'Sg*P
public void setSFilePath(String value) /NCN wAj7
{ ]3f[v:JQ
sFilePath = value; ]k7%p>c=B
} {2P18&=
l/zv >
pFNU~y'Kf
public String getSFileName() C5I7\9F)
{ ~//E'V-
return sFileName; tJ>>cFx
} ,-E'059
n9={D
KhB775
public void setSFileName(String value) 6?<lS.s
{ 9S}rTZkEq
sFileName = value; ~i?A!
} z|%Pi J,
0{bl^#$f
ki@C}T5
public int getNSplitter() &DGz/o
{ 0,DrVGa
return nSplitter; >L4F'#I
} kG!hqj
d!R+-Fp
qwj7CIc(
public void setNSplitter(int nCount) nf"#F@dk
{ 'hBnV xd&
nSplitter = nCount; `Tyd1!~
} 1Xm>nF~
} Q}lCQK/g
{._'Q[
a7ZufB/
/* /Z^a,%1
**Utility.java V^[&4
*/ #vyf*jPr
package NetFox; aaY AS"/:
[5p9p1@u{C
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public class Utility { bs)wxU`Q*
Tt~[hC h
SIrNZ^I
public Utility() -A w]b} #v
{ 8o%Vn'^t
rY^uOrR>j*
9Q s5e
} *,lDo9
L k nK
//线程睡眠 W)Y`8&,
public static void sleep(int nSecond) PL$XXj>|:
{ &>+T*-'
try{ QH(&Cu,
Thread.sleep(nSecond); Ii[U%
} @hg[v`~
catch(Exception e) L QV@]z&
{ mm:TR?^
e.printStackTrace (); k $^/$N
} Ka(B&.
} ZXYyG`3+
zi6J|u
//日志 v0 :n:q
public static void log(String sMsg) `f~bnL
{ #`|Nm3b
System.err.println(sMsg); T]&?^QGAZ
} Y(7&3+'K
dNt^lx
uVU)LOx
public static void log(int sMsg) ' abEY
{ EEZ~Bs}d
System.err.println(sMsg); ,S`n?.&& 7
} IWq\M,P
} t.;._'
M]{~T7n-
Jaw1bUP!oK
/* pIK:$eN!/
**TestMethod.java B(s^(__]
*/ PsNrCe%e
package NetFox; Ij4q &i"
-avxH?;?7
A? B+
public class TestMethod { Q<V1`e
u,8)M'UU
'12*'Q+{+
public TestMethod() Het"x
{ ///xx/weblogic60b2_win.exe tb~E.Lm\
try{ +?"F=.SZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M}11 tUl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *> nOL
SiteFileFetch fileFetch = new SiteFileFetch(bean); Gy):hGgN
fileFetch.start(); &K'*67h
} %zGv+H?
catch(Exception e){e.printStackTrace ();} l59\Lo:
AeEdqX)
|33t5}we
} L{jx'[C
Jb*QlsGd
6ZHeAb]"
public static void main(String[] args) iLBORT!;
{ ]}b
new TestMethod(); F5x*#/af
} e'$[PF
} Rjq\$aY}%
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