http断点续传简单实现（java)

/* z;fi  
**SiteFileFetch.java (x"TM),Q  
*/ xweV8k/  
package NetFox; Rd#V,[d  
import java.io.*; 9'tOF  
import java.net.*; =gG_ %]``R  
[,_4#Zz  
3JnBKh\n  
public class SiteFileFetch extends Thread { Dj0`#~  
%#g9d  
t>]wWYy  
SiteInfoBean siteInfoBean = null; //文件信息Bean ~
_|OGp_a  
long[] nStartPos; //开始位置 .@7J8FS*  
long[] nEndPos; //结束位置 ZMFV iE;8  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 D H}gvV  
long nFileLength; //文件长度 60*;a*cy  
boolean bFirst = true; //是否第一次取文件 #A&(b}#:o  
boolean bStop = false; //停止标志 Nw74T  
File tmpFile; //文件下载的临时信息 YSQB*FBz  
DataOutputStream output; //输出到文件的输出流 tp4/c'w;)J  
~k}>CNTr  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） 4&TTPcSt;  
public SiteFileFetch(SiteInfoBean bean) throws IOException !4gyrNS  
{ UBN^dbP*  
siteInfoBean = bean; ~i3/Ec0\  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ze5Hg'f  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ?uiQ'}
 
if(tmpFile.exists ()) e<Pbsj  
{ 1a|Z!Vzi  
bFirst = false; ?=C?3R  
read_nPos(); <[N"W82p  
} w"p,6Ew
 
else e@B
+\1  
{ \=kre+g  
nStartPos = new long[bean.getNSplitter()]; c(:qid  
nEndPos = new long[bean.getNSplitter()]; +1`Zu$|  
} z@\r V@W5  
~KtA0BtC  
Y6
J7N^  
N|G=n9p  
} ^Md
]e<WAp  
k{fTqKS%h  
qT U(]O1  
public void run() O^tH43C  
{ !kzC1U  
//获得文件长度 86.LkwlqoH  
//分割文件 xUp[)B6?:  
//实例FileSplitterFetch D'dE!CAUs  
//启动FileSplitterFetch线程 *TacVp  
//等待子线程返回 QE
Ur+7[  
try{ mQV
c ZV  
if(bFirst) GQZLOjsop  
{ ?k6PH"M  
nFileLength = getFileSize(); >o\s'i[  
if(nFileLength == -1) =x8F!W}Bt<  
{ AYB =iLa  
System.err.println("File Length is not known!"); J?Y1G<&  
} t")+L{  
else if(nFileLength == -2) %&D,|Yl6  
{ Cpyv@+;D  
System.err.println("File is not access!"); hJ)>BeH0  
} pWU3
?U  
else b?h
)~j5  
{ ) ?AlQA  
for(int i=0;i<nStartPos.length;i++)  ppwjr +  
{ Y6_%HYI$  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); < C{-ph  
} bo;;\>k  
for(int i=0;i<nEndPos.length-1;i++) Cd>GY  
{ x2 s%qZ#  
nEndPos = nStartPos[i+1]; 1-HL#y*7$  
} }]8n3&*  
nEndPos[nEndPos.length-1] = nFileLength; D/T&0  
} HkGA$  
} H,/|pP.  
dMcCSwYh  
bzI!;P1&  
//启动子线程 zvvF9  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tcovMn'  
for(int i=0;i<nStartPos.length;i++) Cfizh@<  
{
xjm|ewo  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(),
|7ga9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f?-=&||f78  
nStartPos,nEndPos,i); {i:5XL   
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &}TfJ=gj  
fileSplitterFetch.start(); k>W5ts2+  
} KJ7[DN'(  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), me-:A:si  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /3MTutM|<X  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", HwE1cOT  
nEndPos = " + nFileLength); 
qbrf;`  
// fileSplitterFetch[nPos.length-1].start(); yM
dAe>@  
@uIY+_E40g  
lq4vX^S  
//等待子线程结束 Lk%u(duU^  
//int count = 0; 6$]p;}#  
//是否结束while循环 _h@s)"  
boolean breakWhile = false; Hh/Z4`&yi  
5if4eitS  
]6W;~w%  
while(!bStop) e ]@Ex  
{ (}$~)f#s  
write_nPos(); 6mawcK:7  
Utility.sleep(500); qDOJ;>I  
breakWhile = true; 2u0dn?9\  
C'iJFfgR  
IaxzkX_48  
for(int i=0;i<nStartPos.length;i++) .EOHkhn  
{ XHKVs  
if(!fileSplitterFetch.bDownOver) (kECV8)2  
{ ZBDEE+8e  
breakWhile = false; (-lu#hJ`&r  
break; N8$MAW  
} /xK5%cE>B  
} c|f)k:Q  
if(breakWhile) D$sG1*@s-  
break; k+(UpO=/*  
S Z@ JzOA  
1wx&
/#a  
//count++; MX3ss,F  
//if(count>4) h6!o,qw"  
// siteStop(); ya+eGD@N':  
} p1dqDgF*  
i(eLE"G+  
9Y9pKTU  
System.err.println("文件下载结束！"); E8-8E2i,  
} @$5!
  
catch(Exception e){e.printStackTrace ();} ELx?ph-9  
} !&~8j7{  
>[4;K&$B  
myp}DI(  
//获得文件长度 Y,v8eOo45S  
public long getFileSize() kg2?IL  
{ ?}QHEk:H  
int nFileLength = -1; }m?1IU%q  
try{ tDuQ+|~M  
URL url = new URL(siteInfoBean.getSSiteURL()); P,S$qD*4  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sFR'y.  
httpConnection.setRequestProperty("User-Agent","NetFox"); 8[\(*E}d!X  
l)PEg PSRV  
+6vm4(3?  
int responseCode=httpConnection.getResponseCode(); 9]Q\Pr\Ub$  
if(responseCode>=400) ~=t,g S  
{ 7\'ow|)}v  
processErrorCode(responseCode); IN? A`A  
return -2; //-2 represent access is error 97H2hYw9l  
} -j%!p^2j9  
]jWe']T  
R/H?/  
String sHeader; OL{U^uOh
Y  
m6qmZ2<  
+C~,q{u  
for(int i=1;;i++) %4Nq T  
{ O5PCR6U  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 
bSW!2#~  
//Utility.log(in.readLine()); F,CQAgx  
sHeader=httpConnection.getHeaderFieldKey(i); h[()!\vBy  
if(sHeader!=null) F,^<  
{ []K5l%  
if(sHeader.equals("Content-Length")) M5C}*c9  
{ PVAs# ~  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {7`eR2#Wq  
break; MB<oWH[e)  
} RH,(8.&>r  
} urT!?*g,  
else `pp"htm   
break; >@b70X!J]  
} &[BDqi  
} UQl3Tq4QM  
catch(IOException e){e.printStackTrace ();} nq#k}Qx:  
catch(Exception e){e.printStackTrace ();} -9"hJ4  
f-5vE9G3y7  
^>?gFvWB%  
Utility.log(nFileLength); 5 ^}zysY`  
S3-3pJ]~Zk  
[YT"UVI  
return nFileLength; C7%+1w'D8  
} $CaF"5}?Ke  
6MfjB@  
;4nz'9+  
//保存下载信息（文件指针位置） EthnI7Y  
private void write_nPos() clz6;P  
{ *Yk3y-   
try{ w{[OtGIi3  
output = new DataOutputStream(new FileOutputStream(tmpFile)); pCSR^ua>  
output.writeInt(nStartPos.length); 7Rr(YoWa  
for(int i=0;i<nStartPos.length;i++) C& 0iWY\a  
{ /nEh,<Y)  
// output.writeLong(nPos); E Kks8  
output.writeLong(fileSplitterFetch.nStartPos); [w
AI;=.  
output.writeLong(fileSplitterFetch.nEndPos); "}PaMR]  
} D_,}lsrb  
output.close(); -#v1b>ScY  
} =@b/Gl  
catch(IOException e){e.printStackTrace ();} 3_(fisvx  
catch(Exception e){e.printStackTrace ();} n!mtMPH$  
} be`\O  
,R=Mr}@u
 
C?Dztkz  
//读取保存的下载信息（文件指针位置） ~={8b  
private void read_nPos() VsOn j~@  
{ =iy%;>I`  
try{ TD+V.}  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); X:\r )  
int nCount = input.readInt(); fZ6lnZ  
nStartPos = new long[nCount]; tk4~ 8  
nEndPos = new long[nCount]; yG?,8!/]  
for(int i=0;i<nStartPos.length;i++) bit&H  
{ //VgPl  
nStartPos = input.readLong(); +*[lp@zU{  
nEndPos = input.readLong(); ;4of7d  
} kS[xwbE  
input.close(); |yiM7U,i  
} t&(}`W  
catch(IOException e){e.printStackTrace ();} C|c'V-f  
catch(Exception e){e.printStackTrace ();} d^X;XVAvP  
} UJ1Ui'a(!!  
D0,U2d  
hVRpk0IJDK  
private void processErrorCode(int nErrorCode) #KZ6S9>@
 
{ Ji SJi?  
System.err.println("Error Code : " + nErrorCode); hKb-l`KO  
} 9J_lxy}  
X b-q:{r1h  
A P><l@  
//停止文件下载 g"|QI=&_J  
public void siteStop() fB[I1Z  
{ vINm2%*zJ  
bStop = true; M(o?I}  
for(int i=0;i<nStartPos.length;i++) l)`bm/k]V  
fileSplitterFetch.splitterStop(); y4s]*?Wz  
1]#qxjZ~  
[;II2[5 ,  
} ]V J$;v'{[  
} <R>qOX8  
//负责部分文件的抓取 9RwD_`D(MN  
**FileSplitterFetch.java HF}%Ow  
*/ } pE<P;\]k  
package NetFox; #/t^?$8\\  
Pq`]^^=be'  
^R\0<\'  
import java.io.*; WlU^+ctS  
import java.net.*; b Mi,z3z  
v-2O{^n  
vMK
mHq  
public class FileSplitterFetch extends Thread { 2'tZ9mK  
k'Fc:T8:~5  
Be"D0=<  
String sURL; //File URL =mYY8c Yl  
long nStartPos; //File Snippet Start Position oqOv"yLJ:  
long nEndPos; //File Snippet End Position |lAu6d !  
int nThreadID; //Thread's ID r>4.{\C  
boolean bDownOver = false; //Downing is over jgbUZP4J>  
boolean bStop = false; //Stop identical qsn
6i%VH  
FileAccessI fileAccessI = null; //File Access interface Fy8KZWim  
!]4'f/  
;>Y,b4B;  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fb[f >1|  
{ &'9 Jy'(X  
this.sURL = sURL; a)GLz  
this.nStartPos = nStart; *A.E?9pL\  
this.nEndPos = nEnd; %CJgJ,p
k>  
nThreadID = id; TO.?h!  
fileAccessI = new FileAccessI(sName,nStartPos);//定位
~]BxM9  
} 6-U|
e|e  
O]RP?'vO  
vttmSdY  
public void run() {tMpI\>S  
{
w
QJY,|.  
while(nStartPos < nEndPos && !bStop)  UN[rW0*  
{ 5an#,vCn{  
L31B:t^  
PpX=~Of~  
try{ 'S\YNLqQ  
URL url = new URL(sURL); {0F\Y+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :VC#\/f  
httpConnection.setRequestProperty("User-Agent","NetFox"); poj@G{  
String sProperty = "bytes="+nStartPos+"-"; &yN@(P)  
httpConnection.setRequestProperty("RANGE",sProperty); v??}d   
Utility.log(sProperty); 7k}[x|u  
_3DRCNvh  
j#r|t
+{"C  
InputStream input = httpConnection.getInputStream(); 74hGk
f^S  
//logResponseHead(httpConnection); 0TK+R43_  
2[: *0 DV#  
/ 2>\Z(  
byte[] b = new byte[1024]; znv2
:  
int nRead; XNkw9*IT  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W*iPseXq  
{ x0B|CO  
nStartPos += fileAccessI.write(b,0,nRead); WgPpW!`  
//if(nThreadID == 1) K4NB#
 
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #FKo:id`K  
}
o^%4w>|  
Q.Uyl:^PxU  
0\#uxzdhJ  
Utility.log("Thread " + nThreadID + " is over!"); DZKVZ_q  
bDownOver = true; O?|opD  
//nPos = fileAccessI.write (b,0,nRead); q\*",xZxwz  
} DJP)V8]!B  
catch(Exception e){e.printStackTrace ();} ~.7r  
} UO$z_ p]w  
} nAv@^G2  
R4v)}`x  
EeC5HgIU'C  
//打印回应的头信息 "mr;!"LA  
public void logResponseHead(HttpURLConnection con) #!0le:_  
{ \TqKm  
for(int i=1;;i++) T(%U$ea-S  
{ 3OTq  
String header=con.getHeaderFieldKey(i); FC+K2Yf1=0  
if(header!=null) ~Q%C>  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #?L%M  
Utility.log(header+" : "+con.getHeaderField(header)); :[P>e ox  
else {` Bgxejf  
break; N
)G.^9  
} \tE
2@  
} n}X)a-=  
9^l_\:4  
8&:  *<  
public void splitterStop() bv,_7UOG  
{ ?<VahDBS+A  
bStop = true; $$`E@\5P  
} i2`i5&*  
"mr;|$Y  
i3g;B?54  
} E&r*[;$  
o!EPF-:  
Qa~dd{?  
/* 3lYM(DT  
**FileAccess.java N}Ozm6
Mc  
*//文件访问(定位，写) ~jMdM~}  
package NetFox; wZN<Og+;  
import java.io.*; lSU&Yqx  
'zV/4iE=  
d4<Ic#  
public class FileAccessI implements Serializable{ yEL^Y'x?  
S?*pCJ0  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i)=!U>B_0  
RandomAccessFile oSavedFile; >J>4g;Y  
long nPos;
wjYwQ=y5  
6?OH"!b2-}  
H)aeSF5  
public FileAccessI() throws IOException GPnd7}Tn  
{ HT7V} UiaO  
this("",0); M?pu7wa  
} '}h[*IB}5  
qg?O+-+  
Fn0Rq9/@  
public FileAccessI(String sName,long nPos) throws IOException )? WiO}"  
{ OLpE0gZ.|`  
oSavedFile = new RandomAccessFile(sName,"rw"); v`8dRVN  
this.nPos = nPos; y)_T!&ze  
oSavedFile.seek(nPos); Pda(O;aNU  
} &A>Hq/Y  
sxcpWSGA^  
RbUBKMZU  
public synchronized int write(byte[] b,int nStart,int nLen) +`g&J  
{ Z7?C^m  
int n = -1; TIlBT{A<  
try{ b?`8-g  
oSavedFile.write(b,nStart,nLen); z1A[rbe=4w  
n = nLen; _uU}J5d.  
} ~3
 4Ly  
catch(IOException e) ]5b%r;_  
{ %IGcn48J  
e.printStackTrace (); _KVge)j  
} b6BeOR*ps  
RMU]GCa  
zMasA  
return n; Zn&S7a>7  
} X]d["  
l%@>)%LA  
>(+g:p  
} Qe<DX"  
V4p4m@z^u  
WMfu5x7e4  
/* /=co/}i  
**SiteInfoBean.java 8d.5D&  
*/ VaQqi>;\  
package NetFox; to@ O  
G3vKA&KZ  
-Gjz;/s%XH  
public class SiteInfoBean { qD:3;85  
bf]W_I]B  
$r})j
~c  
private String sSiteURL; //Site's URL M;*f(JY$  
private String sFilePath; //Saved File's Path {2?o:  
private String sFileName; //Saved File's Name v#i,pBj  
private int nSplitter; //Count of Splited Downloading File 2OFrv=F  
3]Rb2$p[=  
J{c-'Of2yi  
public SiteInfoBean() `[x`#irD  
{//nSplitter的缺省值为5 iDej{95  
//default value of nSplitter is 5 xKIzEN &  
this("","","",5); "F%w{bf  
} ta\AiHm  
_/0vmgQ&  
!U38aHG  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &x$1hx'  
{ @KRr$k  
sSiteURL= sURL; .T0w2Dv/  
sFilePath = sPath; Stqlp<xy  
sFileName = sName; kx=.K'd5H  
this.nSplitter = nSpiltter; Cw"Y=`  
pX3Q@3,$  
mEsOYIu{  
} Y(QLlJ*)/  
Ia-`x/r*m  
E'qGKT  
public String getSSiteURL() >g8H  
{ D.?Rc'yD  
return sSiteURL; ~_^#/BnAl  
} k fS44NV  
0 =#)-n  
h6c0BmS{1  
public void setSSiteURL(String value) t3%[C;@wB  
{ FTvFtdY  
sSiteURL = value; j?sq i9#  
} '?Fw]z1$  

K4938 v  
-Bymt[  
public String getSFilePath() 2u
w1R;zw  
{ 9&e=s<6dO  
return sFilePath; {,z$*nf  
} 3dm lP2  
;`
<uo$R  
ir^%9amh  
public void setSFilePath(String value) g_8Bhe"ik  
{ ;w,+x 7  
sFilePath = value; 8nn%wps  
} .*+?]  
9Qja|;  
CD|)TXy  
public String getSFileName() PMPB}-d  
{ .{U@Hva_K  
return sFileName; ?CSc5b`eo  
} gaeMcL_^a  
8!87p?Mz  
R_iQLBr
d  
public void setSFileName(String value) f4F13n_0X  
{ wxw3t@%mNm  
sFileName = value; hxcRFqX"  
} 9 -7.4!]I  
{.=4;  
R:49Gn:F  
public int getNSplitter() HmxA2 ~C  
{ $RA8U:Q!1e  
return nSplitter; 
Nm;(M=  
} Hrb67a%b  
7q_B`$ata  
@&!`.Y oy  
public void setNSplitter(int nCount) Th&-n%r9K  
{ 8%-+@\=  
nSplitter = nCount; KI&+Zw4VL  
} EXt?xiha?  
} sp%EA=: E  
Jv*[@ -.k  
rGjP|v@3^  
/* iDp'M`(6h  
**Utility.java uLok0"}  
*/ @uru4>1_dy  
package NetFox; J
'99  
@wa2Z  
9C;Hm>WEpP  
public class Utility { 'n1-?T)  
QkMK\Up  
c@p4,G  
public Utility() # `}(x;ge  
{ !brXQj8D7  
H(}Jt!/:  
QoagyL  
} 92y<E<n  
Rw8l"`  
//线程睡眠 9='a9\((mH  
public static void sleep(int nSecond) !V|%n(O"  
{ v X=zqV  
try{ 6:Eu[PE~w  
Thread.sleep(nSecond); Aj|Gqw>  
} e)
Q{yO  
catch(Exception e) C*O648yz[  
{ 
HR0t[*  
e.printStackTrace (); !YJfP@"e6r  
} =*K~U# uoC  
} |^z?(?w  
<G d?,}\  
//日志 WO=X*One  
public static void log(String sMsg) *=+m;%]_  
{ C)w11$.YQ9  
System.err.println(sMsg); Cso!VdCX  
} s{IXth6  
6g\SJO-;N  
tG1,AkyZ  
public static void log(int sMsg) r?^[o  
{ N!O.=>8<  
System.err.println(sMsg); H"~]|@g-p  
} BK,h$z7#6  
} T)QZ9a  
0UV5}/2rP  
JY$B%R4;]  
/* rU
^?Z  
**TestMethod.java Yc5{M*w  
*/ l5?fF6#j  
package NetFox; ;=.i+  
2L=+z1%I  
6O|B'?]Pf  
public class TestMethod {
hN(sz  
if|j)h&  
M6$9-  
public TestMethod() EVovx7dr  
{ ///xx/weblogic60b2_win.exe !uIT5D  
try{ SkGh@\  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0I|IL]JL  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )HLe8:PG~  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?`& l Y  
fileFetch.start(); M]\p9p(_  
} .u
u[f2.N+  
catch(Exception e){e.printStackTrace ();} P F#X8+&J  
(``EBEn  
CYIp 3D'k  
} uU_0t;oR3  
l| /tKW  
y^M~zOe  
public static void main(String[] args) -68E]O  
{ xLUgbql-  
new TestMethod(); F%Te0l  
} hXxgKi%  
} q]1HCWde  
点击下载更多相关资料