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
  • 11955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
/* G#'Q~N  
**SiteFileFetch.java 'hy?jQ'|e  
*/ $wgc vySx  
package NetFox; a0{[P$$  
import java.io.*; v*vn<nPAQ>  
import java.net.*; p}&Md-$1  
y]<#%Fh  
Wge ho  
public class SiteFileFetch extends Thread { Ia'x]#~  
u8^Y,LN  
Jxn3$  
SiteInfoBean siteInfoBean = null; //文件信息Bean }E,jR=@  
long[] nStartPos; //开始位置 Nr%(2[$ =  
long[] nEndPos; //结束位置 0K/G&c?;=  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ]L$4P y  
long nFileLength; //文件长度 Hw y5G ;  
boolean bFirst = true; //是否第一次取文件 JxnuGkE0[#  
boolean bStop = false; //停止标志 l:q8Pg)  
File tmpFile; //文件下载的临时信息 T G_bje  
DataOutputStream output; //输出到文件的输出流 CJv> /#$/F  
xM%`K P.8X  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) _HLC>pH~#  
public SiteFileFetch(SiteInfoBean bean) throws IOException /%5_~Jkr,  
{ ;m' '9z)2  
siteInfoBean = bean; E*OG-r   
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); A3z/Bz4]:#  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); YWSz84d  
if(tmpFile.exists ()) =?HzNA$yh  
{ ,%[LwmET  
bFirst = false; J"5jy$30'$  
read_nPos(); =w?M_[&K)  
} ^l--zzO 8l  
else zuk"  
{ cxY$LY!zX  
nStartPos = new long[bean.getNSplitter()]; >dyhox2*"  
nEndPos = new long[bean.getNSplitter()]; amMjuyW  
} (=`Z0)=  
[gpOu TW  
q Frt^+@  
"/Om}*VhD  
} {K<uM'ww>  
{>wI8  
m"<4\;GK  
public void run() 1B6C<cL:sU  
{ 8~.iuFp  
//获得文件长度 ';&0~[R[  
//分割文件 Q! Kn|mnN  
//实例FileSplitterFetch kkT3 wP  
//启动FileSplitterFetch线程 kJI3`gS+  
//等待子线程返回 m5)EQE}gPp  
try{ xLe =d|6  
if(bFirst) E2Us#a  
{ @+iC/  
nFileLength = getFileSize(); 4 #aqz9k  
if(nFileLength == -1) %)8d{1at  
{ I ca3  
System.err.println("File Length is not known!"); 4sb )^3T  
} .F4oo=  
else if(nFileLength == -2) y+?=E g  
{ w~4 z@/^"p  
System.err.println("File is not access!"); HmhUc,EC  
} /X@7ju;   
else :-w@^mli  
{ #m[vn^8B]y  
for(int i=0;i<nStartPos.length;i++) @55bE\E?@  
{ ^I@ey*$  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ]Mn&76 fu  
} `<S/?I8  
for(int i=0;i<nEndPos.length-1;i++) ZEL/Ndk  
{ $< A8gTJ  
nEndPos = nStartPos[i+1]; ftO+.-sm<  
} {-o7w0d_  
nEndPos[nEndPos.length-1] = nFileLength; D}mo\  
} ^uC"dfH  
} CKx\V+\O  
h0T< :X   
c=jcvDQ6W  
//启动子线程 Uc\|X;nkRk  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; '&N: S-  
for(int i=0;i<nStartPos.length;i++) 2_Pz^L  
{ [&1iF1)4  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !O~}, pp  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8rGl&  
nStartPos,nEndPos,i); A,3@j@bdy  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =t@:F  
fileSplitterFetch.start(); h~,x7]w6  
} }/_('q@s\  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =ZCH1J5"  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y*`:M(  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nsZDZ/jx  
nEndPos = " + nFileLength); 8dr0 DF$c  
// fileSplitterFetch[nPos.length-1].start(); W3FymCI  
F"-S~I7'L  
NdM}xh  
//等待子线程结束 p^p'/$<6_  
//int count = 0; 2dv|6p  
//是否结束while循环 U#8\#jo  
boolean breakWhile = false; D9}d]9]$  
"B3iX@C  
bs:C1j\&  
while(!bStop) )EhTM-1  
{ "g x5XW&  
write_nPos(); @:S$|D~  
Utility.sleep(500); TvQWdX=  
breakWhile = true; p3V9ikyy  
A28ZSL  
@uQ%o%Ru6  
for(int i=0;i<nStartPos.length;i++) r$b:1C~  
{ !JT< (I2  
if(!fileSplitterFetch.bDownOver) gUks O!7^1  
{ on]\J  
breakWhile = false;  ~Y1"k]J  
break; Hi9 G^Q  
} B$K7L'e+-  
} p5lR-G  
if(breakWhile) ;e&hM\p  
break; Ytl:YzXCi  
o@qN#Mg?>}  
F@>w&A ~K  
//count++; =_#ye}E  
//if(count>4) &@mvw=d  
// siteStop(); ZrmnQ  
} {%]NpFg#b  
{. s]\C  
fMWXo)rzj  
System.err.println("文件下载结束!"); ?9o#%?6k  
} @/_XS4  
catch(Exception e){e.printStackTrace ();} hXV4$Dai  
} /V#MLPA  
5A0K V7N5  
nG&w0de<>  
//获得文件长度 T+ &x{+gZ  
public long getFileSize() h1Ke$#$6  
{ sq8tv]  
int nFileLength = -1; N&R '$w  
try{ U92B+up-  
URL url = new URL(siteInfoBean.getSSiteURL()); f9h:"Dnzin  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OlD7-c2L]  
httpConnection.setRequestProperty("User-Agent","NetFox"); 0hH Iz4(  
sRkz WMl  
9b{g+lMZo  
int responseCode=httpConnection.getResponseCode(); nr 'YWW  
if(responseCode>=400) |YG)NO  
{ "wc`fg"3  
processErrorCode(responseCode); [15hci+-  
return -2; //-2 represent access is error &*V0(  
} UiGUaBmF*  
~G|{q VO7A  
b?+ Yo>yF8  
String sHeader; w]]x[D]L  
? RrC~7~  
5n|MA  
for(int i=1;;i++) Li?{e+g  
{ @Z3[ c[D)9  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &lXx0 "-$  
//Utility.log(in.readLine()); ~2, wI<Nz  
sHeader=httpConnection.getHeaderFieldKey(i); Og&0Z)%  
if(sHeader!=null) SdEb[  
{ F1Zk9%L%9$  
if(sHeader.equals("Content-Length")) \K4CbZ,.  
{ 1s^$oi}  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kVB}r.NHP  
break; L!G9O]WB  
} ^>P@5gcoE(  
} 3rXL0&3w%  
else Ep v3/ `I  
break; <.y^  
} O"2wV +9  
} |-cALQ  
catch(IOException e){e.printStackTrace ();} b&|YQW} ~  
catch(Exception e){e.printStackTrace ();} hc@;}a\Y  
ey9fbS ^I  
!0d9<SVC  
Utility.log(nFileLength); he#Tr'j  
0qaG#&!  
`#IT24!  
return nFileLength; W~W?<%@  
} *aSRKY  
T$>=+U  
IdC k  
//保存下载信息(文件指针位置) 6):sO/es  
private void write_nPos() 3'gd'`Hn/  
{ egIS rmL+X  
try{ 34O+#0<y~  
output = new DataOutputStream(new FileOutputStream(tmpFile)); f|[5&,2<  
output.writeInt(nStartPos.length); 4n.i<K8K[  
for(int i=0;i<nStartPos.length;i++) lHj7O &+  
{ 9X^-)G>  
// output.writeLong(nPos); J^<j=a|D  
output.writeLong(fileSplitterFetch.nStartPos); epY;1,; >  
output.writeLong(fileSplitterFetch.nEndPos); b`;b}ug  
} a#^4xy:  
output.close(); c_DB^M!h  
} K{[Fa,]'  
catch(IOException e){e.printStackTrace ();} Z{R=h7P  
catch(Exception e){e.printStackTrace ();} .+ yJh  
} EC\rh](d 1  
PauFuzPP  
wtgO;w  
//读取保存的下载信息(文件指针位置) D$^7Xhk  
private void read_nPos() =f{Z~`3  
{  }@Ll!,  
try{ tg m{gR  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,y{fqa4  
int nCount = input.readInt(); 5G]#'tu  
nStartPos = new long[nCount]; COl%P  
nEndPos = new long[nCount]; d+$[EDix  
for(int i=0;i<nStartPos.length;i++) (}7o a9Q<  
{ \2LA%ZU  
nStartPos = input.readLong(); ,~68~_)  
nEndPos = input.readLong(); Se]t;7j  
} <3]/ms  
input.close(); .q& ]wu  
} HpgN$$\@  
catch(IOException e){e.printStackTrace ();} P^{`d_[K%  
catch(Exception e){e.printStackTrace ();} =_~'G^`tu  
} t+Tg@~K2[>  
C(Ba r#  
CEJG=*3  
private void processErrorCode(int nErrorCode) @0x.n\M_  
{ (V |q\XS  
System.err.println("Error Code : " + nErrorCode); !*QA;*e  
} C&MqUj"]  
}v|[h[cZ  
]r{ #268  
//停止文件下载 l9Cy30O6  
public void siteStop() &wWGZ~T  
{ I>(z)"1  
bStop = true; b*%WAVt 2T  
for(int i=0;i<nStartPos.length;i++) b|pNc'u:Cn  
fileSplitterFetch.splitterStop(); dIh(~KqB  
# JT%]!  
&T4Cn@  
} _\V{X}ftqa  
}  kc/H  
//负责部分文件的抓取 LAjw!QB  
**FileSplitterFetch.java mjJlXA  
*/ 3 mMdq*X5  
package NetFox; a*ixs'MJ  
O8}s*}]  
U";Rp&\3;  
import java.io.*; Z-r0 D  
import java.net.*; gZuR4Ti  
N pIlQaMo4  
;]ZHD$g  
public class FileSplitterFetch extends Thread { bsS| !KT  
vf'jz`Z  
UgBY ){<  
String sURL; //File URL ,}xC) >  
long nStartPos; //File Snippet Start Position J'&? =|  
long nEndPos; //File Snippet End Position )pj \b[  
int nThreadID; //Thread's ID 'aSORVq^e[  
boolean bDownOver = false; //Downing is over 78}%{7YY  
boolean bStop = false; //Stop identical =:T:9Y_i  
FileAccessI fileAccessI = null; //File Access interface ,PtR^" Mf4  
GTX&:5H\t  
(IWd?,H,n  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e @MCumc~+  
{ $7ME a"a  
this.sURL = sURL; %-zH]"Q$  
this.nStartPos = nStart; =>TtX@Q{  
this.nEndPos = nEnd; $TUC?e9"h  
nThreadID = id; w@D@,q'x  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >}`1'su  
} '3 ,JL!  
-cS4B//IK8  
`>HthK  
public void run() Wa<NId  
{ t"m`P1  
while(nStartPos < nEndPos && !bStop) Z-=7QK.\{  
{ &]A1 _dy  
%x)U8  
P>cJ~F M  
try{ Lgw@y!Llij  
URL url = new URL(sURL); kxiyF$ 9  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +Gs;3jC^  
httpConnection.setRequestProperty("User-Agent","NetFox"); m^&mCo,  
String sProperty = "bytes="+nStartPos+"-"; *^m.V=  
httpConnection.setRequestProperty("RANGE",sProperty); ? 9M+fi  
Utility.log(sProperty); B,qZwc|  
yD'h5)yu  
T</gWW  
InputStream input = httpConnection.getInputStream(); 81 Not  
//logResponseHead(httpConnection); o ieLh"$  
^hTJp{  
YXOD fd%L  
byte[] b = new byte[1024]; tg4&j$  
int nRead; c8 fb)`,k  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w'j]Y%  
{ !,WRXE&j  
nStartPos += fileAccessI.write(b,0,nRead); F}mwQ%M  
//if(nThreadID == 1) t$Ji{t-  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z%d4V<fn  
} ]nGA1S{  
@k;3$  
DxG'/5jQ[  
Utility.log("Thread " + nThreadID + " is over!"); {:+^[rer j  
bDownOver = true; U/l ra&P  
//nPos = fileAccessI.write (b,0,nRead); Y'":OW#oN  
} v2<gkCK^  
catch(Exception e){e.printStackTrace ();} rW .0_*  
} 6:X\vw  
} l"g%vS,;`  
"TCbO`mg  
e 2&i  
//打印回应的头信息 f)fw87UPc  
public void logResponseHead(HttpURLConnection con) alD|-{Bf  
{ >}tG^)os  
for(int i=1;;i++) m$j;FKz+|  
{ ImW~Jy  
String header=con.getHeaderFieldKey(i); e/%Y ruzS  
if(header!=null) rx) Q]  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -B! TA0=oJ  
Utility.log(header+" : "+con.getHeaderField(header)); k18V4ATE]  
else vK/Z9wR*05  
break; WWz ns[$f  
} oMf h|B  
} l$@lk?dc  
y$W3\`2q  
!0_Y@>2  
public void splitterStop() q&x#S_!  
{ "lAS <dq  
bStop = true; FV,SA3  
} mjc:0hH  
09i[2n;O  
7guxkN#  
} iIRigW  
4H '&5  
%^A++Z$`  
/* qa#F}aGd  
**FileAccess.java ^DJ U99  
*//文件访问(定位,写) T!$HVHh&,}  
package NetFox; LZ$!=vg4  
import java.io.*; Qk?Jy<Ra  
x$4'a~E  
gW%(_H mX  
public class FileAccessI implements Serializable{ [X\2U4  
b&&'b )  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 w%na n=  
RandomAccessFile oSavedFile; cE?J]5#^  
long nPos; yx4c+(J^8  
cV,URUD  
;pYk+r6Cr  
public FileAccessI() throws IOException qN(; l&Q  
{ pm|]GkM  
this("",0); 3j#F'M)s{  
} *2hzReM  
Cl=ExpX/O  
m#P&Yd4T  
public FileAccessI(String sName,long nPos) throws IOException )`0 j\  
{ kv2:rmv  
oSavedFile = new RandomAccessFile(sName,"rw"); H%V[% T4=  
this.nPos = nPos; 3iwZUqyq  
oSavedFile.seek(nPos); 7?@v}%w  
} <ZEll[0L  
CdjGYS  
w?"l4.E%  
public synchronized int write(byte[] b,int nStart,int nLen) ->UrWW^  
{ v.J#d>tvf  
int n = -1; zc5_;!t  
try{  }2"k:-g  
oSavedFile.write(b,nStart,nLen); s6IuM )x  
n = nLen; *O2j<3CHf  
} uLht;-`{n  
catch(IOException e) r 6<}S(  
{ $tJJ >"  
e.printStackTrace (); 2q bpjm  
} (6b%;2k  
GW#Wy=(_  
L x&ZWF$  
return n; XFYl[?`G  
} X8TZePh  
[0emOS  
75ob1h"  
} 1:8: yFV  
ce\-oT  
YFY)Z7fK  
/* Q2uE_w`B  
**SiteInfoBean.java V2X(f6v  
*/ -fv.ByyA  
package NetFox; J %t1T]y~  
jrR~V* :k  
ycN_<  
public class SiteInfoBean { I._=q  
i)ctrdP-  
=r2d{  
private String sSiteURL; //Site's URL H'.d'OE:I  
private String sFilePath; //Saved File's Path -mF9Skj  
private String sFileName; //Saved File's Name mBF?+/l  
private int nSplitter; //Count of Splited Downloading File &3efJ?8  
7Fx8&Z  
# ,Y}  
public SiteInfoBean() r`@Dgo}  
{//nSplitter的缺省值为5 IYFA>*Es  
//default value of nSplitter is 5 FdD'Hp+  
this("","","",5); L $~Id  
} lHU$A;  
YDwns  
+gkB  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g`1i[Iu2  
{ N C& 1l]  
sSiteURL= sURL; 4$rO,W/&0  
sFilePath = sPath; |qD<h  
sFileName = sName; s.U p<Rw  
this.nSplitter = nSpiltter; @{G(.S  
pI4<` K  
V& m\  
} j!l(ReGb  
L[^e< I  
*4bV8T>0Z  
public String getSSiteURL() *!/9?M{p  
{ ScD9Ct*):C  
return sSiteURL; n9%rjS$  
} D+U^ pl-  
_1 a2Z\  
7RZ7q@@fgh  
public void setSSiteURL(String value) h ? M0@Z  
{ sq%f%?(V  
sSiteURL = value; 0IZV4{  
} vzU%5,  
[,c>-jA5  
NTC,Vr\A  
public String getSFilePath() PSE![whK  
{ 7?4>'  
return sFilePath; f"Z2&Y@  
} k`d  
Wd7*sa3T  
udB}`<Q  
public void setSFilePath(String value) VC@o]t5  
{ eP)RP6ON{  
sFilePath = value; *QLbrR  
} q^s$4q  
Ugn"w E  
nsPM`dz/  
public String getSFileName() E4{8 $:q=  
{ \,WPFV  
return sFileName; GM5::M]fS  
} mxIEg?r(  
m{g{"=}YR  
<D__17W:;  
public void setSFileName(String value) 1~+w7Ar =(  
{ 5)vXmAD/0  
sFileName = value; l"+=z.l6;  
} bvoR?D\-"  
xn-n{U"  
#pZ3xa3R  
public int getNSplitter() 8yd OS  
{ 6l4l74  
return nSplitter; p(v.sP4w  
} QAR<.zXvP  
(b(iL\B$D=  
MKbW^:  
public void setNSplitter(int nCount) \oi=fu=}*  
{ *+ 7#z;  
nSplitter = nCount; <X: 9y  
} 7L!k9"X`0F  
} h:|aQJG5  
nPKj%g3h  
A 9u9d\  
/* #pIb:/2a_  
**Utility.java [mm5?23g  
*/ P6MT[  
package NetFox; *+ b[v7  
$ZA71TzMV  
`18G 5R  
public class Utility { <+6)E@Y  
Q$3%aR-2  
 8NLk`/  
public Utility() Eq|_> f@@8  
{  :S.0e  
L"IdD5`7T  
rn(T Z}  
} E]68IuP@'  
s>kzt1,x  
//线程睡眠 v8LKv`I's  
public static void sleep(int nSecond) )0NA*<Q+.  
{ us/x.qPy2  
try{ n04Zji(F@  
Thread.sleep(nSecond); k'm!|  
} HxkhlNB  
catch(Exception e) sp JB6n(  
{ #q%&,;4  
e.printStackTrace (); c(o8uWn  
} oM< 9]jK}  
} IkD\YPL;  
.7oz  
//日志 [ z?<'Tj  
public static void log(String sMsg) BsxQW`>^y  
{ f;QWlh"9  
System.err.println(sMsg); NbSwn}e_  
} f@Db._ E  
'E6)6N  
myH#.$=A  
public static void log(int sMsg) !bQ5CB  
{ zE<}_nA  
System.err.println(sMsg);  MgA6/k  
} 8}4V$b`Z  
} 9]l7 j\L  
m#Rll[  
O4 [[9  
/* {4 *ob@w*  
**TestMethod.java B&"fPi  
*/ fk=_ Y  
package NetFox; ucyxvhH^-  
0rF{"HM~  
_Nw-|N.  
public class TestMethod { /KH3v!G0  
syMB~g  
8USF;k  
public TestMethod() euQ d  
{ ///xx/weblogic60b2_win.exe Fe8xOo6  
try{ 3rs=EMz:w  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >*EcX3  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E: #VS~  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7,Nd[ oL*7  
fileFetch.start(); k{uc%6s  
} V0"UFy?i  
catch(Exception e){e.printStackTrace ();} JWC{"6  
!YCYmxw#  
L[D}pL=  
} !x[ +rf  
D/rKqPp|!  
{um~]  
public static void main(String[] args) Y8(g8RN  
{ dKhDO`.s  
new TestMethod(); Y!}BmRLh2  
} {R\"x|  
} aabnlOVw  
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
欢迎提供真实交流,考虑发帖者的感受
认证码:
验证问题:
10+5=?,请输入中文答案:十五