http断点续传简单实现（java)

/* Fb\ E39  
**SiteFileFetch.java 0Q!/A5z  
*/ yGvBQ2kYb  
package NetFox; [K""6D  
import java.io.*; xt1Ug~5  
import java.net.*; ,j e  
*
IWWD\U  
)8*}-z  
public class SiteFileFetch extends Thread { p&k%d, *  
XNQPyZ2@|b  
l-?#oy  
SiteInfoBean siteInfoBean = null; //文件信息Bean g<g$c<sm  
long[] nStartPos; //开始位置 DLD5>  
long[] nEndPos; //结束位置 JiFB<Q\  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ErxvGB
(2  
long nFileLength; //文件长度 2U@:.S'K  
boolean bFirst = true; //是否第一次取文件 =buarxk  
boolean bStop = false; //停止标志 (CInt_dBw~  
File tmpFile; //文件下载的临时信息 B,U|

V  
DataOutputStream output; //输出到文件的输出流 qFN`pe,  
aW_Pv~  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） g9@H4y6fe=  
public SiteFileFetch(SiteInfoBean bean) throws IOException gubw&W  
{ {JQCfs  
siteInfoBean = bean; (Rh$0^)A  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); wWQt  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); mjKu\7F  
if(tmpFile.exists ()) qi$nG_<<Z  
{ 5Zn:$?7  
bFirst = false; 5QP`2I_n  
read_nPos(); 1|:'jK#gE  
} ^J'O8G$  
else /Xl(>^|&  
{ 17#t7Yk  
nStartPos = new long[bean.getNSplitter()];
^~^=$fz  
nEndPos = new long[bean.getNSplitter()]; 9D]bCi\  
} 1>L8EImx]V  
kQD~v+u{`  
E8L\3V4  
'0v]?mM  
} Hi nJ}MF  
|f1RhB  
sKC(xO@L;`  
public void run() Cd|rDa  
{ XZT|ID_u"  
//获得文件长度 pgPm0+N  
//分割文件 SB,#y>Zv?  
//实例FileSplitterFetch #j'7\SV  
//启动FileSplitterFetch线程 mFt\xGa  
//等待子线程返回 v%7Gh-P  
try{ L@.Trso  
if(bFirst) Y>x3`f]  
{ .|0$?w  
nFileLength = getFileSize(); 08/Tk+  
if(nFileLength == -1) }U?:al/m  
{ U/ax`_  
System.err.println("File Length is not known!"); V`@/"Djj  
} +xQj-r)-  
else if(nFileLength == -2) `
aSbGMz  
{ 5t|$Yt[  
System.err.println("File is not access!"); Zt}b}Bz  
} 8S5Q{[!  
else KQ0f2?  
{ =.l>Uw!  
for(int i=0;i<nStartPos.length;i++) f8-~&N/_R  
{ >7z(?nQYT^  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); qe/5'dw  
} S<z8  
for(int i=0;i<nEndPos.length-1;i++) &%tW  
{ jOZ>^5}  
nEndPos = nStartPos[i+1]; SeuDJxqopD  
} m~4ik1wq  
nEndPos[nEndPos.length-1] = nFileLength;
3Xy~ap>Y  
} {\X$vaF  
} GK1P7Qy?V  
Jl|^^?  
_+Z5qUmQ  
//启动子线程 z\YLO%Mm  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >1HXC2 Y  
for(int i=0;i<nStartPos.length;i++) uX6p^KNm5  
{ wbI1~/  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q_dMuoI  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0IZF%`  
nStartPos,nEndPos,i); 5g.Kyj|  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); OTNI@jQ)  
fileSplitterFetch.start(); v^ v \6uEP  
} j%}9tM6[  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dF5y' R'  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /m i&7C(6  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &8I*N6p:%/  
nEndPos = " + nFileLength); }PM7CZSq  
// fileSplitterFetch[nPos.length-1].start(); mQ9shdvt-  
bf.yA:~U  
24wr=5p]Q  
//等待子线程结束 F+L%Ho;@P  
//int count = 0; `i+2YCk  
//是否结束while循环 '&$zgK9T?  
boolean breakWhile = false; FF0~i+5  
/SyAjZ  
:B\$7+$v  
while(!bStop) -9Ygn_M  
{ ?y__ V
rw  
write_nPos(); &VcO,7 A|  
Utility.sleep(500); LBmXy8'T`  
breakWhile = true; [)il_3t  
rq1zvuUx  
D(WV
k  
for(int i=0;i<nStartPos.length;i++) JIqg[Mao  
{ @Kw&X
Ke`  
if(!fileSplitterFetch.bDownOver) m"6K_4r]  
{ 1&vR7z]*  
breakWhile = false; tu/4  
break; DghqSL^s  
} ):A.A,skf  
} [Dmf.PUe  
if(breakWhile) ",#Ug"|2  
break; KC%&or  
o 9(x\g  
8 qZbsZi4  
//count++; (cV1Pmn  
//if(count>4) "KSdC8MS  
// siteStop(); /LtbmV  
} N/<c;"o  
q8
,,[R_  
J)|I/8!#  
System.err.println("文件下载结束！"); M@p<L VP  
} G*~CB\K_  
catch(Exception e){e.printStackTrace ();} +_QcLuV,  
} x<@i3Y{[  
Dtyw]|L\H  
Q'?VLv|@  
//获得文件长度 Ekh)l0 l  
public long getFileSize() t2|0no  
{ JXR]G  
int nFileLength = -1; jl>wvY||  
try{ !lA~;F  
URL url = new URL(siteInfoBean.getSSiteURL()); K@:Ab'(P^|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NzN"_ojM  
httpConnection.setRequestProperty("User-Agent","NetFox"); (]10Z8"fJ  
=WEDQ\ c  
Rm6i[y&  
int responseCode=httpConnection.getResponseCode(); ;Cjj_9e,:  
if(responseCode>=400) 3II*NANeg  
{ =.JcIT'  
processErrorCode(responseCode); @x;(yqOb  
return -2; //-2 represent access is error Fq%NY8KNE  
} Vs Z7n~e  
77wod}h!:  
j0w@ \gO<  
String sHeader; ULs'oT)K;  
%;<g!Vw.k  
YkFERIa076  
for(int i=1;;i++) Y##lFEt  
{ Vock19P  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); BWB}bq  
//Utility.log(in.readLine());
)h{+pK  
sHeader=httpConnection.getHeaderFieldKey(i); /x_AWnU  
if(sHeader!=null) e-1G\}E  
{ yL -}E  
if(sHeader.equals("Content-Length")) [$:L|V!{  
{ xDsKb_  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u1d%wOY  
break; rhly.f7N=A  
} {+3g*s/HI  
} C}DIm&))  
else e<FMeg7n  
break; z+CX$
.Z  
} BN&}g}N  
} %?[0G,JG  
catch(IOException e){e.printStackTrace ();} ! CJ*zZ*  
catch(Exception e){e.printStackTrace ();} vo2GFo  
xO,;4uE  
c~OvoTF,  
Utility.log(nFileLength); 6s ~!B{Q  
kg,\l9AM  
4^d).{&X  
return nFileLength; <
s$T7Zk  
} w
fcR[  
tF./Jx]_  
6UL9+9[C  
//保存下载信息（文件指针位置） 9]1LwX!M2  
private void write_nPos() (A=Z,ed  
{ AN|f:259  
try{ E\cX  
output = new DataOutputStream(new FileOutputStream(tmpFile)); o)DO[  
output.writeInt(nStartPos.length); $jv"$0Fc  
for(int i=0;i<nStartPos.length;i++) ~`B]G  
{ ra_v+HR7  
// output.writeLong(nPos); _={mKKoHs  
output.writeLong(fileSplitterFetch.nStartPos); #v9+9X`1L  
output.writeLong(fileSplitterFetch.nEndPos); *Tr{a_{~C  
} QXl~a%lB  
output.close(); "pH;0
[r]  
} Kxz|0l  
catch(IOException e){e.printStackTrace ();} rls{~ZRl  
catch(Exception e){e.printStackTrace ();} D]|{xKC}  
} D";clP05K  
8s-X H  
peOoZdJd  
//读取保存的下载信息（文件指针位置） 9
>`dB  
private void read_nPos() }m7$,'C%P  
{ FP*kA_z$  
try{ #TH(:I=[  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _9Rj,  
int nCount = input.readInt(); lIO#)>  
nStartPos = new long[nCount]; K]|hkp&  
nEndPos = new long[nCount]; {eQijW2Z3  
for(int i=0;i<nStartPos.length;i++) ziM@@$.F  
{ s'IB{lJ9  
nStartPos = input.readLong(); 9jNh%raG|  
nEndPos = input.readLong(); P6=5:-Hh  
} C',uY7}<  
input.close(); +RkXe;q  
} /V#?d  
catch(IOException e){e.printStackTrace ();} z3>4 xn{  
catch(Exception e){e.printStackTrace ();} Fzy#!^9Nu  
} I }8b]  
<p2\;\?4z  
D>Rlm,U  
private void processErrorCode(int nErrorCode) qG g29  
{ }9;mtMR$  
System.err.println("Error Code : " + nErrorCode); 8qxZ7|Y@  
} M 8(w+h{  
Xh/BVg7$  
~lqNWL^l  
//停止文件下载 Ag8lI+ h  
public void siteStop() dk]A,TB*2  
{ D-x*RRkpp  
bStop = true; s%6L94\t  
for(int i=0;i<nStartPos.length;i++) NdXC8  
fileSplitterFetch.splitterStop(); 5D XBTpCVM  
@3FQMs4  
&h=f  
} +
~M.VsX  
} 1'dZ?`O  
//负责部分文件的抓取 TD4 n%k.  
**FileSplitterFetch.java M8y|Lm}o  
*/ dP]Z:  
package NetFox; ,_=LV  
;<xPzf  
:/RvtmW  
import java.io.*; Fx)><+-  
import java.net.*; lTtc#  
~*Y/#kPY  
Uv=)y^H~*A  
public class FileSplitterFetch extends Thread { */$]k
E  
HW"5MZ8E  
x`'s  
String sURL; //File URL %>y!N!.F  
long nStartPos; //File Snippet Start Position 7;?7q  
long nEndPos; //File Snippet End Position F*NHy.Y  
int nThreadID; //Thread's ID dwiLu&]u  
boolean bDownOver = false; //Downing is over Gvr>n@n  
boolean bStop = false; //Stop identical V|{~9^  
FileAccessI fileAccessI = null; //File Access interface :X7O4?ww  
zn|O)"C  
?
,[$8V  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |O"Pb`V+  
{ r"\<+$ 7  
this.sURL = sURL; pF}E`U=Z  
this.nStartPos = nStart; kY'C'9p  
this.nEndPos = nEnd; L[Wi[S6=)g  
nThreadID = id; &[yYgfs
p  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "39mhX2  
} 6k+tO%{~  
XZ3M~cDq  
VjZb\ d4  
public void run() gAsjkNt?  
{ ?;w\CS^Qu  
while(nStartPos < nEndPos && !bStop) S>"
C}F$X  
{ \D#+0  
2t=&h|6EW  
x'%vL",%  
try{ u(ETc*D
]  
URL url = new URL(sURL); ?b(DDQMf  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eV0eMDY5  
httpConnection.setRequestProperty("User-Agent","NetFox"); !yKrA|w1  
String sProperty = "bytes="+nStartPos+"-"; 'p%w_VbI  
httpConnection.setRequestProperty("RANGE",sProperty); !8RJHMX&  
Utility.log(sProperty); ma`sv<f4-!  
y35e3  
@Qqf4h  
InputStream input = httpConnection.getInputStream(); =Prz|
 
//logResponseHead(httpConnection); Cth<xn(Q  
Nvd(Tad  
KT<N ;
[;  
byte[] b = new byte[1024]; li}>xDSQ4  
int nRead; ^[2siG  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) clIn}wQ  
{ JNu+e#.Y  
nStartPos += fileAccessI.write(b,0,nRead); Yg1HvSw\  
//if(nThreadID == 1) HLE%f;  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XhOg>  
} 1}CJ&  
.O{_^~w_q  
,^@/I:  
Utility.log("Thread " + nThreadID + " is over!"); G/KTF2wl7  
bDownOver = true; i \.&8  
//nPos = fileAccessI.write (b,0,nRead); +^4HCyW  
} "m}N hoD4  
catch(Exception e){e.printStackTrace ();} 8BnsYy)j  
} SQJ4}w>i  
} Ek '%%%  
n."XiXsN  
ZP.~Y;Ch;-  
//打印回应的头信息 !nF.whq  
public void logResponseHead(HttpURLConnection con) ]TsmWob  
{ 3C#Sr6  
for(int i=1;;i++) 1EliR uJ  
{ : p7PiqQ  
String header=con.getHeaderFieldKey(i); u4[rA2Bf8E  
if(header!=null) <!?ZH"F0  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Oc/ i'  
Utility.log(header+" : "+con.getHeaderField(header)); $,1KD3;+]  
else $ Vsf?ID  
break; DM{Z#b]  
} s>ZlW:jY  
} 
G-D
OI  
e.;B?0QrV  
1_)Y{3L  
public void splitterStop() &LhR0A  
{ ,.uI>  
bStop = true;
?a~#`<  
} x\5\KGw16  
OUm,;WNLf  
en16hd>^W:  
} ^<Sy{KY  
twql)lbx  
EB5^eNdL  
/* &t74T"(d  
**FileAccess.java nD{{/_"'  
*//文件访问(定位，写) Odbm"Y  
package NetFox; }A7]bd  
import java.io.*; l'"Ici#7Ls  
kBrU%[0O  
K1-y[pS]E  
public class FileAccessI implements Serializable{ w?M` gl8r  
o 0H.DeP  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U5H5QW+  
RandomAccessFile oSavedFile; }9Awv#+  
long nPos; ljk,R G  
v`~egE17  
uSNlI78D  
public FileAccessI() throws IOException WI\h@qSB  
{ jN sM&s,  
this("",0); $Q56~AP  
} !F#^Peb  
r-c1_ [Q#  
p~Mw^SN'  
public FileAccessI(String sName,long nPos) throws IOException cu"ge]},  
{ EZ)GW%Bm2  
oSavedFile = new RandomAccessFile(sName,"rw"); w)%/Me3o  
this.nPos = nPos; VJ|80?4h  
oSavedFile.seek(nPos); RVa{%  
} b@)nB  
X5o{d4R L  
C)+%9Edg  
public synchronized int write(byte[] b,int nStart,int nLen) C'fQ Z,r-v  
{ jg=}l1M"  
int n = -1; _t\)W(E&  
try{ @i@f@.t  
oSavedFile.write(b,nStart,nLen); 3 bll9Ey  
n = nLen; 9I*`~il>{  
} &,iPI2`O A  
catch(IOException e) '8UhYwyr  
{ tcj3x<  
e.printStackTrace (); (KdP^.7  
} ^97\TmzP{  
AR5)Uws  
2B=+p83<  
return n; 7>yb8/J  
} =
1% <  
7N[Cs$_]  
c:_dW;MJ0  
} YC d  
>I;J!{  
zZ{(7Kfz  
/* <'z.3@D  
**SiteInfoBean.java _}:#T8h  
*/ uZ(,7>0  
package NetFox; A=pyaU`aE  
&3bhK5P  
xX2/uxi8  
public class SiteInfoBean { "!_,N@\t  
@!2vS@f  
(c1Kg
  
private String sSiteURL; //Site's URL OiMr,  
private String sFilePath; //Saved File's Path (j884bu  
private String sFileName; //Saved File's Name CeW}zkcT  
private int nSplitter; //Count of Splited Downloading File ueV,p?Wo  
V?o%0
V  
AWz|HF#-  
public SiteInfoBean() HWi: CDgm  
{//nSplitter的缺省值为5 )dZ1$MC[  
//default value of nSplitter is 5 ;>h:VnV(>(  
this("","","",5); =U+_;;F=  
} #kPsg9Y  
TWTh!  
u13v@<HGc  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %Y<3v\`_  
{ H4JwgQ  
sSiteURL= sURL; 7DCu#Y[  
sFilePath = sPath; [p&2k&.XYe  
sFileName = sName; C9"yu&l  
this.nSplitter = nSpiltter; L<H6AzR+  
,ku3;58O<  
`ls^fnJTpf  
} _"'0^F$I  
/H<tv5mXJ  
G.sf>
.[  
public String getSSiteURL() NM&R\GI  
{ SH#!Y  
return sSiteURL; _Q6` Wp6m  
} *d$r`.9j  
g,d'&r"JWt  
dn|OY.`|  
public void setSSiteURL(String value) `beU2N  
{ tboc7Hor4  
sSiteURL = value; cux<7#6af  
} 1n|K   
%8~g#Z  
+a!uS0fIJi  
public String getSFilePath() !S5_+.U#  
{ }ec3qZ@  
return sFilePath; d2[R{eNX=  
} $J)2E g  
o1]ZeF  
rv;is=#1  
public void setSFilePath(String value) /dq(Z"O_  
{ R1NwtnS  
sFilePath = value; B{\qYL/~  
} tA]Y=U+Q  
d0 qc%.s  
UJhUb)}^  
public String getSFileName() hT?|:!ED.F  
{ l fJ lXD  
return sFileName; +W[NgUrGJ  
} +N:=|u.g  
fs6% M]u  
Tg\wBhJr|  
public void setSFileName(String value) &24$*Oe  
{ :zLeS-  
sFileName = value; Ki(  
} diDB>W  
*zTEK:+_  
c},wW@SF2W  
public int getNSplitter() Z]x)d|3;  
{ gL}x|Q2`  
return nSplitter; t'im\_$F  
} XL!^tMk  
5;_&C=[  
i*2l4  
public void setNSplitter(int nCount) x>m=n_  
{ Zz@wbhMV  
nSplitter = nCount; K6M_b?XekA  
} mqk tM6  
} )9'Zb`n  
do&0m[x%  

}hA h'*(  
/* z((9vi W  
**Utility.java +!Lz]@9K  
*/ SJXP}JB_  
package NetFox; +#MQ8d  
Xl\yOMfp  
8PtX@s43\  
public class Utility { Q3|I.I e  
'e5,%"5(c  
iyr'9BA  
public Utility() IM$I=5ye  
{ F`U YgN  
-VPda @@w  
gPzp/I  
} xA {1XS}  
FErKr)  
//线程睡眠 fw+ VR.#2H  
public static void sleep(int nSecond) 7R5!(g  
{ {u_2L_  
try{ ruTj#tWSo  
Thread.sleep(nSecond); QLum=YB  
} rtY4B~_  
catch(Exception e) r,-9]?i  
{ QB|D_?]  
e.printStackTrace (); AagWswv{Bf  
} 4,P!D3SH  
} kFo&!  
^":Dk5gl  
//日志 Jk3V]u  
public static void log(String sMsg) OJ2I (8P  
{ ~sUWXw7~  
System.err.println(sMsg); l<YCX[%E  
} c0M>CaKD  
?~#{3b  
I!uGI  
public static void log(int sMsg) v'W`\MKY)  
{ GYM6 `  
System.err.println(sMsg); K`%
I!Br  
} PquATAzQA  
} y.m;4((  
i1JWdHt  
Owz.C_{)  
/* jYi{[**  
**TestMethod.java GtNGrJU  
*/ 9}DF*np`G  
package NetFox; =gb(<`{>  
oHI/tS4 _  
 T24?1  
public class TestMethod { ?g~g GQV  
+HxL>\  
z`Cq,Sz/  
public TestMethod() 6 SosVE>Z  
{ ///xx/weblogic60b2_win.exe =-GHs$u%f  
try{ Ap[}[:U  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m&X6a C'[  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U&<Nhh  
SiteFileFetch fileFetch = new SiteFileFetch(bean); '5n67Hl 1  
fileFetch.start(); o)hQ]d  
} .0zNt  
catch(Exception e){e.printStackTrace ();} (`&`vf  
d|8iD`sZz  
Qy+&N*k>  
} 6Wabw:  
m+m,0Ey5H  
-n`igC  
public static void main(String[] args) /Xds+V^Z  
{ +Eh^j3W  
new TestMethod(); *NDM{WB|)  
} AqzPwO^  
} G`HL^/Z*  
点击下载更多相关资料