社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 10993阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* 9Bz0MUbrLl  
**SiteFileFetch.java 62[8xn=(%  
*/ 740B\pc0  
package NetFox; m9$a"$c  
import java.io.*; )6{< i5nJ\  
import java.net.*; Nt]qVwUm'Y  
#;[Bl=3(  
@%1IkvJV  
public class SiteFileFetch extends Thread { MRfb[p3Cx  
-DP*q3  
!9;)N,  
SiteInfoBean siteInfoBean = null; //文件信息Bean =O!|IAe#  
long[] nStartPos; //开始位置 /.R<,/gj  
long[] nEndPos; //结束位置 X\Y}oa."A  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 F8<"AI  
long nFileLength; //文件长度  G2`${aMS  
boolean bFirst = true; //是否第一次取文件 hQRL,?  
boolean bStop = false; //停止标志 vE%s, E,  
File tmpFile; //文件下载的临时信息 ~6`iY@)  
DataOutputStream output; //输出到文件的输出流 *5k+t  
FJeiY#us  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) gAt~?HvW6  
public SiteFileFetch(SiteInfoBean bean) throws IOException h}Rx_d  
{ i?>tgmu.  
siteInfoBean = bean; 0:"2MSf>  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); mdW~~-@H  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); F";.6%;AC  
if(tmpFile.exists ()) F;8*H1  
{  c 6"Ib)  
bFirst = false; ;au*V5a%  
read_nPos(); %'bJ:  
} VfSj E.|  
else e_.Gw"/Yl  
{ :^i^0dC  
nStartPos = new long[bean.getNSplitter()]; p[9s<lEh  
nEndPos = new long[bean.getNSplitter()]; |mhKIis U  
} R_ ZK0ar  
H4:&%"j7  
s$w;q\1z  
LlHa5]E@6  
} edipA P~!  
kJ{+M]pW  
%Jp|z? [/  
public void run() vDFGd-S  
{ AiP!hw/V$  
//获得文件长度 / vxm"CJR  
//分割文件 os4{0Mxu  
//实例FileSplitterFetch u5B:^.:p  
//启动FileSplitterFetch线程 dtZE67KS  
//等待子线程返回 4;<ut$G  
try{ d$t40+v  
if(bFirst) DY\J[l<<  
{ (UL4+ta  
nFileLength = getFileSize(); t~``md4  
if(nFileLength == -1) DF_X  
{ lk3=4|?zsE  
System.err.println("File Length is not known!"); / 3!fA=+  
} tyh@ ^7  
else if(nFileLength == -2) %eg+F  
{ :Y P#  
System.err.println("File is not access!"); d\]Yk]r  
} o`n$b(VZ  
else EON:B>2a  
{ `d\r;cE%lm  
for(int i=0;i<nStartPos.length;i++) W$0^(FH[  
{ K/L;8a  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); t `kui.  
} g%nl!dgS  
for(int i=0;i<nEndPos.length-1;i++) h6~$/`&]b  
{ _n;;][]S  
nEndPos = nStartPos[i+1]; bQ'8SCe  
} 58 bCUh#uw  
nEndPos[nEndPos.length-1] = nFileLength; pav'1d%  
} 9QQyl\  
} - e"jw#B  
\$sjrqKnu  
rG}\Zjn{  
//启动子线程 Hnk:K9u.B:  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _8,()t'"  
for(int i=0;i<nStartPos.length;i++) En{`@JsM  
{ ag-f{UsTy  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3ZEB  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), */:uV B,b2  
nStartPos,nEndPos,i); 3cdTed-MIh  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #>lG7Ns|4  
fileSplitterFetch.start(); _{<seA  
} &i+Ce  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), El\%E"Tk%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0:w"M<80  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", SZaS;hhhHu  
nEndPos = " + nFileLength); ?POUtRN  
// fileSplitterFetch[nPos.length-1].start(); |L2SFB?d=  
,XDRO./+T  
7f rTTSZ  
//等待子线程结束 wE+${B03  
//int count = 0; n3A aZp[  
//是否结束while循环 A,sr[Pa@  
boolean breakWhile = false; 8Nu=^[qwQM  
`]Q:-h  
$9Hcdbdm  
while(!bStop) ;rc`OZyE  
{ UMAgA!s  
write_nPos(); [!!Q,S"  
Utility.sleep(500); /|* Y2ETOr  
breakWhile = true; 93Co}@Y;Y+  
o2<#s)GpY  
:oJ=iB'Zc  
for(int i=0;i<nStartPos.length;i++) 'Ut7{rZ5  
{ hjZKUM G(k  
if(!fileSplitterFetch.bDownOver) 'yMF~r3J  
{ Z&;uh_EC  
breakWhile = false; vZ.x{"n'~  
break; <HbcNE~  
} ``wSc0\  
} s"t$0cH9  
if(breakWhile) >=[(^l  
break;  }Y;K~J  
gNt(,_]ZR  
ZYC<Wb)I  
//count++; 1t)il^p4[;  
//if(count>4) `@nl  
// siteStop(); Q ]}Hd-  
} Lhqz\o  
Y1]n^  
rqY`8Ry2M  
System.err.println("文件下载结束!"); #Y$hNQQ$F  
} ?Y@N`S  
catch(Exception e){e.printStackTrace ();} dq]0X?[6  
} rzt Ru  
ZIQ [bE7  
hEp(A8g)bQ  
//获得文件长度 uD^cxD  
public long getFileSize() yU9DSY\m{  
{ Z<vKQ4 G  
int nFileLength = -1; tCdqh-   
try{ c@893<_  
URL url = new URL(siteInfoBean.getSSiteURL()); Y'8?.a]'  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9jw\s P@  
httpConnection.setRequestProperty("User-Agent","NetFox"); V,cBk  
+F^^c2E  
\--8lH -K  
int responseCode=httpConnection.getResponseCode(); 3.*8)NW  
if(responseCode>=400) ))"6ern  
{ g"}%2~Urf  
processErrorCode(responseCode); ~^1{B\I  
return -2; //-2 represent access is error ,%M$0poKM  
} [5SD_dN  
t+!$[K0/  
MB]<Dyj,  
String sHeader; ;IZwTXu!S  
T(U_  
E>D_V@,/  
for(int i=1;;i++) 0"f\@8r(  
{ 7t0e r'VC  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); % ~H=sjg  
//Utility.log(in.readLine()); ~kEI4}O  
sHeader=httpConnection.getHeaderFieldKey(i); 7_inJ$  
if(sHeader!=null) oYm[V<nIl  
{ |l]XpWV  
if(sHeader.equals("Content-Length")) ^LoUi1j  
{ a6)BqlJ  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Yfzl%wc  
break; %z,m B$LY  
} $#9;)8J  
} T?ZRiR)@  
else h7lDHIQf  
break; {#?N  
} vunHNHltW0  
} ix)M`F%P3  
catch(IOException e){e.printStackTrace ();} 4NheWM6  
catch(Exception e){e.printStackTrace ();} 5YeM%%-S  
,9zjFI  
r\'A i6  
Utility.log(nFileLength); W{6|tx)  
EyJJ0  
4;yKOQD|  
return nFileLength; keL&b/@  
} !>..Q)z  
e D?tLj  
k@RDvn  
//保存下载信息(文件指针位置) 8]/bK5`  
private void write_nPos() _E@2ZnD2  
{ hKL4cpK4  
try{ f!Y?S  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5YE'L.  
output.writeInt(nStartPos.length); DgId_\Ze  
for(int i=0;i<nStartPos.length;i++) sBvzAVBL  
{ .WA-&b_  
// output.writeLong(nPos); qr"3y  
output.writeLong(fileSplitterFetch.nStartPos); `T@i.'X  
output.writeLong(fileSplitterFetch.nEndPos); u8&Z!p\  
} lb4Pcd j  
output.close(); E7j(QO f  
} SJb&m-  
catch(IOException e){e.printStackTrace ();} N +Yxz;Mg  
catch(Exception e){e.printStackTrace ();} jnO9j_CY  
} 6F!+T=  
xpV|\2C  
4&<oFW\r  
//读取保存的下载信息(文件指针位置) i [7\[  
private void read_nPos() ^}/PGG\~r  
{ =Y{(%sn  
try{ 89pEfl j2  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %g{X?  
int nCount = input.readInt(); h7G"G"  
nStartPos = new long[nCount]; V_ :1EBzz  
nEndPos = new long[nCount]; J=9FRC  
for(int i=0;i<nStartPos.length;i++) P{kur} T  
{ /M1ob:m  
nStartPos = input.readLong(); ey7 f9  
nEndPos = input.readLong(); +h|`/ &,  
} %(3|R@G.  
input.close(); +"\sc;6m.  
} P+@/O  
catch(IOException e){e.printStackTrace ();} t<.)Z-Ii  
catch(Exception e){e.printStackTrace ();} n{n52][J]  
} dk[!V1x4\  
yj 3cyLXw  
5d Eh7XL  
private void processErrorCode(int nErrorCode) SYAyk  
{ Pr':51(  
System.err.println("Error Code : " + nErrorCode); Q{sH3Y#l  
} #xsE3Wj-X  
##,a0s^  
&#{Z( h.de  
//停止文件下载 V\ZGd+?  
public void siteStop() UOv+T8f=  
{ k9sh @ENy  
bStop = true; XRM_x:+]  
for(int i=0;i<nStartPos.length;i++) $v4.sl:x  
fileSplitterFetch.splitterStop(); JFcLv=U  
>*~L28Fyn  
:3v}kLO7|  
} ^S4d:-.3  
} b[r8 e  
//负责部分文件的抓取 PCHu #5j_a  
**FileSplitterFetch.java DU0zez I9  
*/ M'?,] an  
package NetFox; ZQ4p(6a   
%aG5F}S2~  
%". HaI]  
import java.io.*; [L3=x;U  
import java.net.*; hci6P>h<ia  
? &o2st  
pA'4|ffwe  
public class FileSplitterFetch extends Thread { zqimR#u  
cvn@/qBq*t  
"%`1 ]Fr  
String sURL; //File URL dU&a{ $ku[  
long nStartPos; //File Snippet Start Position <Th6r.#?  
long nEndPos; //File Snippet End Position yZ0-wI  
int nThreadID; //Thread's ID g!g#]9j  
boolean bDownOver = false; //Downing is over jD$,.AVvz  
boolean bStop = false; //Stop identical "@e3EX7h  
FileAccessI fileAccessI = null; //File Access interface =_.l8IYX$%  
dN$0OS`s[  
e>} s;H,  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Nyku4r0  
{ (yH'{6g\  
this.sURL = sURL; [^WC lRF  
this.nStartPos = nStart; Fco`^kql.D  
this.nEndPos = nEnd; {{$Nqn,pH  
nThreadID = id; %0S3V[4I  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7x"R3  
} +SP{hHa^  
nHM~  
R5N%e%[  
public void run() ]~Rho_mq#  
{ JrJo|0Q  
while(nStartPos < nEndPos && !bStop) iOd&B B6  
{ u(z$fG:g  
qk%;on&`  
ih58 <Up5  
try{ 66g9l9wm(  
URL url = new URL(sURL); S5gyr&dm  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y z<3JRw  
httpConnection.setRequestProperty("User-Agent","NetFox"); u0JB\)(-/h  
String sProperty = "bytes="+nStartPos+"-"; UFXaEl}R   
httpConnection.setRequestProperty("RANGE",sProperty); B{QBzx1L9c  
Utility.log(sProperty); T;Lkaxsn  
w#ZoZZ wh  
5dx$HE&b)  
InputStream input = httpConnection.getInputStream(); -RE^tW*Yy  
//logResponseHead(httpConnection); 3atBX5  
{ }:#G  
1h^:[[!c  
byte[] b = new byte[1024]; m]'#t)B_m  
int nRead; y*4=c _Z  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :vmH]{R  
{ GSoX<*i  
nStartPos += fileAccessI.write(b,0,nRead); RVZ")Z(  
//if(nThreadID == 1) $h+1u$po  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .T}Wdn g  
} QVv#fy1"6  
P}Gj %4/G  
M,j U}yD3  
Utility.log("Thread " + nThreadID + " is over!"); aZH:#lUlj  
bDownOver = true; bZ dNibN  
//nPos = fileAccessI.write (b,0,nRead); @3>u@  
} f/U`  
catch(Exception e){e.printStackTrace ();} rlMLW  
} j b!x:  
} mUNn%E:7@{  
$jjfC  
p\Q5,eg  
//打印回应的头信息 BGvre'67  
public void logResponseHead(HttpURLConnection con) FI)17i$  
{ [@&m4 7  
for(int i=1;;i++) %vn|k[n D  
{ 'f#{{KA  
String header=con.getHeaderFieldKey(i); PIJr{6B/PA  
if(header!=null) K%,2=.  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h){0rX@:&  
Utility.log(header+" : "+con.getHeaderField(header)); @D]5civm_  
else ^ sOQi6pL  
break; =J18eH!]  
} E~DQ-z  
} uu-PJTNZ  
-"R2  
#Vnkvvv  
public void splitterStop() ;!>rnxB?4  
{ J! AgBF N4  
bStop = true; I&fozO   
} U&g@.,Y#  
$POu\TO  
)cW#Rwu_A4  
} gt\E`HB8E  
3$9s\<j  
O\ GEay2  
/* ]tim,7s  
**FileAccess.java z{8bvuE  
*//文件访问(定位,写) KWq+PeB5TS  
package NetFox; B?OFe'*  
import java.io.*; o8 IL $:  
WO7z  
Bj+S"yS  
public class FileAccessI implements Serializable{ h8x MI  
AgWa{.`f:  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &9.Cl;I  
RandomAccessFile oSavedFile; WEw6He;  
long nPos; ,cXD.y  
=%BSKSG.  
a]$1D!Anc  
public FileAccessI() throws IOException j:Xq1f6a  
{ yjO1 Ol  
this("",0); .H escg/S  
} c_dVWh e  
zKyyU}LHH  
YC*"Thuu  
public FileAccessI(String sName,long nPos) throws IOException w0[6t#$F  
{ ZFA`s qT  
oSavedFile = new RandomAccessFile(sName,"rw"); *2ZjE!A  
this.nPos = nPos; [xbSYu,&  
oSavedFile.seek(nPos); {yBs7[Wn  
} 1m'k|Ka  
,[N%Q#  
-$t{>gO#Y  
public synchronized int write(byte[] b,int nStart,int nLen) T tfo^ksw  
{ raW>xOivR  
int n = -1; g!|=%(G=  
try{ k 9_`(nx  
oSavedFile.write(b,nStart,nLen); $CRm3#+ ~  
n = nLen; <KJ/<0l  
} ,A9]CQ  
catch(IOException e) 3BzNi'  
{ !-g{[19\  
e.printStackTrace (); ]dF ,:8  
} D+#E -8  
*-#&K\  
Ij 79~pn  
return n; rExnxQ<e  
} #?RU;1)Cw  
2\R'@L*  
_1!7V3|^  
} xn?a. 3b'  
m1j*mtu  
QpF;:YX^3  
/* vXev$x=w-  
**SiteInfoBean.java DMs,y{v  
*/ b k~( ^!R  
package NetFox; N(O9&L*4fm  
_;W.q7 b]  
{k(g]#pP  
public class SiteInfoBean { hMa]B*o/-  
y>S.?H:P  
?#Ge.D~u  
private String sSiteURL; //Site's URL x" 7H5<  
private String sFilePath; //Saved File's Path |a8iZ9/D6  
private String sFileName; //Saved File's Name J; S (>c  
private int nSplitter; //Count of Splited Downloading File &PL8|w  
!:)s"|=  
3 D6RLu  
public SiteInfoBean() Zj_b>O-V  
{//nSplitter的缺省值为5 _PPy44r2  
//default value of nSplitter is 5 2"COP>  
this("","","",5); MO[2~`,Q!  
} q~rEq%tk  
]yV!  
)"qa kT  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R1Pk TZP&  
{ )tG\vk=@  
sSiteURL= sURL; NxfOF  
sFilePath = sPath; *=) cQeJ  
sFileName = sName; 1kz\IQ{  
this.nSplitter = nSpiltter; )z>|4@,  
Qo>b*Ku;  
@<,X0S  
} .28<tEf  
YP 6` L  
-<6\1J  
public String getSSiteURL() } j<)L,  
{ ~cWAl,(B<F  
return sSiteURL; %Celc#v  
}  Ii6<b6-  
AWcLUe{  
5sdn[Tt##  
public void setSSiteURL(String value) ?}qttj  
{ '|ad_M  
sSiteURL = value; y~(h>gi,x  
} .nTwPrG  
\-L&5x"x  
u^&A W$  
public String getSFilePath() vjLJi nJ/  
{ vp1941P  
return sFilePath; Mc@e0  
} 8."]//V  
8<5]\X  
rW<KKGsRWQ  
public void setSFilePath(String value) +\x,HsUc"  
{ [2>yYr s_=  
sFilePath = value; U] ~$g}!)  
} (DJ"WG  
FSP+?((  
>/{@C  
public String getSFileName() 9K.Vb1&  
{ 1Vsz4P"O $  
return sFileName; A_V]yP  
} ]E7F /O/.  
3^IpE];+:u  
Gq+z/Be  
public void setSFileName(String value) f W!a|?e$  
{ !]42^?GH  
sFileName = value; Ha(c'\T (\  
} ^/)^7\@  
d^@dzNv  
I?]ohG K  
public int getNSplitter() @#<D ^"  
{ Wfu(*  
return nSplitter; '>NCMB{*  
} 7jxslI&F  
?:pP8/y  
0\H\lKcK  
public void setNSplitter(int nCount) |<HPn4 ,X  
{ wYd b*"R  
nSplitter = nCount; [I0:=yJ+  
} \?w2a$?6w  
} !6n_}I-W  
l#m#c6;=  
vV6<^ W:9F  
/* s0\X ^  
**Utility.java ? 8)'oMD  
*/ `V=N*hv`  
package NetFox; @V(*65b2  
t=rEt>n~L  
t;\kR4P  
public class Utility { 81](T<  
bG7O  
cq5jPZ}  
public Utility() 1G"z<v B  
{ ;}7Rjl#  
E08 klC0  
>x/z7v?^I  
} WM Fb4SUR  
C`K?7v3$m  
//线程睡眠 nv GF2(;l  
public static void sleep(int nSecond) 4 <9=5q]  
{ BYpG  
try{ _?<|{O  
Thread.sleep(nSecond); ,qA(\[  
} ^.1)};i  
catch(Exception e) ={_C&57N1  
{ #~#R-   
e.printStackTrace (); ~F7 -HaQJ  
} uYn_? G  
} zxJ]" N  
wi;Br[d  
//日志 6{x(.=  
public static void log(String sMsg) ,kF1T,  
{ ]|!OP  
System.err.println(sMsg); F{Z~ R  
} }e!x5g   
N+++4;  
! _f9NK  
public static void log(int sMsg) YT8vP~  
{ 5}:-h>  
System.err.println(sMsg); ?u-|>N>  
} PbW(%7o(t  
} 7/!8e.M\  
'r4/e-`pK  
]*v dSr-J  
/* j`oy`78O  
**TestMethod.java tU4s'J  
*/ 3XL#0\im?s  
package NetFox; Qr1"Tk7s  
~Am,%"%\  
Cf TfL3(J  
public class TestMethod { H+1-]'g`  
5pj22 s  
E'G4Y-  
public TestMethod() N8k00*p65  
{ ///xx/weblogic60b2_win.exe Hcl(3> Jn2  
try{ K$>%e36Cc  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +s(HOq)b  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &]8P1{  
SiteFileFetch fileFetch = new SiteFileFetch(bean); H!?c\7adX  
fileFetch.start(); U@g4w!$r  
} Jzj1w}?H  
catch(Exception e){e.printStackTrace ();} M1 :uJkO.  
b8~Bazk  
u&`XB|~  
} sA/pVU  
?h.wK  
$@"l#vJPfc  
public static void main(String[] args) os,* 3WO  
{ y603$Cv  
new TestMethod(); IHe/xQ@  
} $8;R[SU6Y  
} ~T9/#-e>BF  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
温馨提示:欢迎交流讨论,请勿纯表情、纯引用!
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八